horros / agavi2

src/date/Calendar.class.php

<?php

// +---------------------------------------------------------------------------+
// | This file is part of the Agavi package.                                   |
// | Copyright (c) 2005-2011 the Agavi Project.                                |
// |                                                                           |
// | For the full copyright and license information, please view the LICENSE   |
// | file that was distributed with this source code. You can also view the    |
// | LICENSE file online at http://www.agavi.org/LICENSE.txt                   |
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// |   indent-tabs-mode: t                                                     |
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// +---------------------------------------------------------------------------+

namespace Agavi\Date;

use Agavi\Translation\Locale;
use Agavi\Translation\TranslationManager;
use Agavi\Util\Toolkit;

/**
 * Ported from ICU:
 *  icu/trunk/source/i18n/calendar.cpp        r22016
 *  icu/trunk/source/i18n/unicode/calendar.h  r22265
 *
 * @package    agavi
 * @subpackage date
 *
 * @author     Dominik del Bondio <ddb@bitxtender.com>
 * @author     The ICU Project
 * @copyright  Authors
 * @copyright  The Agavi Project
 *
 * @since      0.11.0
 *
 * @version    $Id$
 */
abstract class Calendar
{
    const GREGORIAN = 'gregorian';

    /**
     * @var        TranslationManager The translation manager instance.
     * @since      0.11.0
     */
    protected $translationManager;

    /**
     * Returns the translation manager.
     *
     * @return     TranslationManager The translation manager.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @since      0.11.0
     */
    public function getTranslationManager()
    {
        return $this->translationManager;
    }

    /**
     * Initialize the variables to default values.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function initVariables()
    {
        $this->fIsTimeSet = false;
        $this->fAreFieldsInSync = false;
        $this->fAreAllFieldsSet = false;
        $this->fAreFieldsVirtuallySet = false;
        $this->fNextStamp = self::kMinimumUserStamp;
        $this->fTime = 0;

The property $fTime was declared of type double, but 0 is of type integer. Maybe add a type cast?

        $this->fLenient = true;
        $this->fZone = null;
    }

    /**
     * Called by the overload handler in the constructor.
     *
     * @param      TimeZone $zone   The timezone to use.
     * @param      Locale   $locale The locale to use.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function constructorOO(TimeZone $zone, Locale $locale)
    {
        $this->translationManager = $zone->getTranslationManager();
        $this->clear();
        $this->fZone = clone $zone;
        $this->setWeekCountData($locale, null);
    }

    /**
     * Marker for end of resolve set (row or group).
     */
    const RESOLVE_STOP  = -1;

    /**
     * Value to be bitwised "ORed" against resolve table field values for
     * remapping.  Example: (UCAL_DATE | kResolveRemap) in 1st column will cause
     * 'UCAL_DATE' to be returned, but will not examine the value of UCAL_DATE.
     */
    const RESOLVE_REMAP = 32;

    /**
     * The minimum supported Julian day.  This value is equivalent to
     * MIN_MILLIS.
     */
    const MIN_JULIAN                 = -19009842; //  -0x7F000000;  this was recalculated based on MIN_MILLIS

    /**
     * The minimum supported epoch milliseconds.  This value is equivalent
     * to MIN_JULIAN.
     */
    const MIN_MILLIS                 = -1853317152000000.0; // ((MIN_JULIAN - kEpochStartAsJulianDay) * kOneDay)

    /**
     * The maximum supported Julian day.  This value is equivalent to
     * MAX_MILLIS.
     */
    const MAX_JULIAN                 = 23939830.0; // (+0x7F000000)

    /**
     * The maximum supported epoch milliseconds.  This value is equivalent
     * to MAX_JULIAN.
     */
    const MAX_MILLIS                 = 1857534508800000.0; // ((MAX_JULIAN - kEpochStartAsJulianDay) * kOneDay)

    const LIMIT_MINIMUM             = 0;
    const LIMIT_GREATEST_MINIMUM    = 1;
    const LIMIT_LEAST_MAXIMUM       = 2;
    const LIMIT_MAXIMUM             = 3;
    const LIMIT_COUNT               = 4;

    protected static $kCalendarLimits = array(
        //               Minimum        Greatest min            Least max         Greatest max
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // ERA
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // YEAR
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // MONTH
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // WEEK_OF_YEAR
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // WEEK_OF_MONTH
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // DAY_OF_MONTH
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // DAY_OF_YEAR
        array(                 1,                  1,                   7,                   7 ), // DAY_OF_WEEK
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // DAY_OF_WEEK_IN_MONTH
        array(                 0,                  0,                   1,                   1 ), // AM_PM
        array(                 0,                  0,                  11,                  11 ), // HOUR
        array(                 0,                  0,                  23,                  23 ), // HOUR_OF_DAY
        array(                 0,                  0,                  59,                  59 ), // MINUTE
        array(                 0,                  0,                  59,                  59 ), // SECOND
        array(                 0,                  0,                 999,                 999 ), // MILLISECOND
        //    -12*self::kOneHour, -12*self::kOneHour,   12*self::kOneHour,   15*self::kOneHour

52% of this comment could be valid code. Did you maybe forget this after debugging?

        array(         -43200000,          -43200000,            43200000,            54000000 ), // ZONE_OFFSET
        array(                 0,                  0,DateDefinitions::MILLIS_PER_HOUR , DateDefinitions::MILLIS_PER_HOUR ), // DST_OFFSET
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // YEAR_WOY
        array(                 1,                  1,                   7,                   7 ), // DOW_LOCAL
        array(         /*N/A*/-1,          /*N/A*/-1,           /*N/A*/-1,           /*N/A*/-1 ), // EXTENDED_YEAR
        array(  self::MIN_JULIAN,   self::MIN_JULIAN,    self::MAX_JULIAN,    self::MAX_JULIAN ), // JULIAN_DAY
        //                     0,                  0, 24*self::kOneHour-1, 24*self::kOneHour-1

57% of this comment could be valid code. Did you maybe forget this after debugging?

        array(                 0,                  0,           86399999,             86399999 ), // MILLISECONDS_IN_DAY
    );

    /**
     * Returns the current UTC (GMT) time measured in milliseconds since 0:00:00
     * on 1/1/70 (derived from the system time).
     *
     * @return     float The current UTC time in milliseconds.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public static function getNow()
    {
        return time() * DateDefinitions::MILLIS_PER_SECOND;
    }

    /**
     * Gets this Calendar's time as milliseconds. May involve recalculation of
     * time due to previous calls to set time field values. The time specified is
     * non-local UTC (GMT) time.
     *
     * @return     float The current time in UTC (GMT) time, or zero if the
     *                   operation failed.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getTime()
    {
        return $this->getTimeInMillis();
    }

    /**
     * Sets this Calendar's current time with the given UDate. The time specified
     * should be in non-local UTC (GMT) time.
     *
     * @param      float The given UDate in UTC (GMT) time.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function setTime($date)
    {
        $this->setTimeInMillis($date);
    }

    /**
     * Returns the php native DateTime object which represents the time of this
     * object. Also supports dates which are not in the range of a unix timestamp.
     * It will also set the DateTime object to be in the same time zone as this
     * Calendar object.
     * Please note that this method will only work on PHP 5.1.x when you have
     * explicitly enabled the new DateTime support. This restriction does not
     * apply to 5.2 and upwards.
     * When the Calendar object is in the AD era, the result of the conversion
     * is undefined.
     *
     * @return     \DateTime The native DateTime.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @since      0.11.0
     */
    public function getNativeDateTime()
    {
        $dateTimeString = sprintf(
            '%d-%d-%d %d:%d:%d',
            $this->get(DateDefinitions::YEAR), $this->get(DateDefinitions::MONTH) + 1, $this->get(DateDefinitions::DATE),
            $this->get(DateDefinitions::HOUR_OF_DAY), $this->get(DateDefinitions::MINUTE), $this->get(DateDefinitions::SECOND)
        );
        
        $tz = $this->getTimeZone();
        // check if this is a custom timezone (they have GMT+0000 as id and could potentially contain seconds as well, so we allow up to 6 digits)
        if (preg_match('#GMT[+-]\d{4,6}#', $tz->getId())) {
            return new \DateTime($dateTimeString . $tz->formatOffset(false, '', ''));
        } else {
            return new \DateTime($dateTimeString, new \DateTimeZone($tz->getId()));
        }
    }

    /**
     * Gets this Calendar's time as unix timestamp. May involve recalculation of
     * time due to previous calls to set time field values. The time specified is
     * non-local UTC (GMT) time.
     *
     * @return     int The current time in UTC (GMT) time as unix timestamp.
     *
     * @throws     <b>OverflowException</b> when the date can't be represented by
     *                                      an unix timestamp.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @since      0.11.0
     */
    public function getUnixTimestamp()
    {
        $unixTime = floor($this->getTimeInMillis() / DateDefinitions::MILLIS_PER_SECOND);
        $unixTimeInt = (int) $unixTime;
        // lets check if the int can't represent the time anymore
        if ($unixTime != $unixTimeInt) {
            throw new \OverflowException('cannot convert the date ' . $this->get(DateDefinitions::YEAR) . '/' . $this->get(DateDefinitions::MONTH) . '/' . $this->get(DateDefinitions::DATE) . ' into a unix timestamp');
        }
        return $unixTimeInt;
    }

    /**
     * Sets this Calendar's current time with the given unix timestamp. The time
     * specified  should be in non-local UTC (GMT) time.
     *
     * @param      int $timestamp The given date in UTC (GMT) time.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @since      0.11.0
     */
    public function setUnixTimestamp($timestamp)
    {
        $this->setTimeInMillis($timestamp * DateDefinitions::MILLIS_PER_SECOND);
    }

    /**
     * @see        Calendar::getAll()
     *
     * @author     Dominik del Bondio <dominik.del.bondio@bitextender.com>
     * @since      1.0.0
     */
    public function toArray()
    {
        return $this->getAll();
    }

    /**
     * Sets all given time field values.
     *
     * @param      array $data An array using the DateDefinitions::XXX as key
     *                         and the respective value as value.
     *
     * @author     Dominik del Bondio <dominik.del.bondio@bitextender.com>
     * @since      1.0.0
     */
    public function fromArray(array $data)
    {
        foreach ($data as $key => $value) {
            $this->set1($key, $value);
        }
    }
    
    /**
     * Returns the locale option string containing the timezone option set
     * to the timezone of this calendar.
     *
     * @param      string $prefix The prefix which will be applied to the timezone option
     *                            string. Use ';' here if you intend to use several
     *                            locale options and append the result of this method
     *                            to your locale string.
     *
     * @return     string
     *
     * @author     Dominik del Bondio <dominik.del.bondio@bitextender.com>
     * @since      1.0.0
     */
    public function getTimeZoneLocaleOptionString($prefix = '@')
    {
        return Locale::getTimeZoneOptionString($this, $prefix);
    }

    public function __is_equal(Calendar $that)
    {
        return $this->isEquivalentTo($that) && $this->getTimeInMillis() == $that->getTimeInMillis();
    }

    public function __is_not_equal(Calendar $that)
    {
        return !$this->isEquivalentTo($that) || $this->getTimeInMillis() != $that->getTimeInMillis();
    }

    /**
     * Returns TRUE if the given Calendar object is equivalent to this
     * one.  An equivalent Calendar will behave exactly as this one
     * does, but it may be set to a different time.  By contrast, for
     * the operator==() method to return TRUE, the other Calendar must
     * be set to the same time.
     *
     * @param      Calendar the Calendar to be compared with this Calendar
     *
     * @return     bool
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function isEquivalentTo(Calendar $other)
    {
        return  get_class($this)                   == get_class($other) &&
                        $this->isLenient()                 == $other->isLenient() &&
                        $this->getFirstDayOfWeek()         == $other->getFirstDayOfWeek() &&
                        $this->getMinimalDaysInFirstWeek() == $other->getMinimalDaysInFirstWeek() &&
                        $this->getTimeZone()->__is_equal($other->getTimeZone());
    }

    /**
     * Compares the Calendar time, whereas Calendar::operator== compares the
     * equality of Calendar objects.
     *
     * @param      Calendar $when The Calendar to be compared with this Calendar.
     *                            The object may be modified physically
     *
     * @return     bool True if the current time of this Calendar is equal to the
     *                  time of Calendar when; false otherwise.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function equals(Calendar $when)
    {
        return ($this->__is_equal($when) || $this->getTime() == $when->getTime());
    }

    /**
     * Returns true if this Calendar's current time is before "when"'s current
     * time.
     *
     * @param      Calendar $when The Calendar to be compared with this Calendar.
     *                            The object may be modified physically.
     *
     * @return     bool True if the current time of this Calendar is before the
     *                  time of Calendar when; false otherwise.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function before(Calendar $when)
    {
        return ($this->__is_not_equal($when) && $this->getTimeInMillis() < $when->getTimeInMillis());
    }

    /**
     * Returns true if this Calendar's current time is after "when"'s current
     * time.
     *
     * @param      Calendar $when The Calendar to be compared with this Calendar.
     *                            The object may be modified physically.
     *
     * @return     bool True if the current time of this Calendar is after the
     *                  time of Calendar when; false otherwise.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function after(Calendar $when)
    {
        return ($this->__is_not_equal($when) && $this->getTimeInMillis() > $when->getTimeInMillis());
    }

    /**
     * UDate Arithmetic function. Adds the specified (signed) amount of time to
     * the given time field, based on the calendar's rules. For example, to
     * subtract 5 days from the current time of the calendar, call
     * add(DateDefinitions::DATE, -5). When adding on the month or
     * DateDefinitions::DATE field, other fields like date might conflict
     * and need to be changed. For instance, adding 1 month on the date 01/31/96
     * will result in 02/29/96.
     *
     * @param      int $field  Specifies which date field to modify.
     * @param      int $amount The amount of time to be added to the field, in the natural
     *                         unit for that field (e.g., days for the day fields, hours
     *                         for the hour field.)
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function add($field, $amount)
    {
        if ($amount == 0) {
            return;   // Do nothing!
        }

        // We handle most fields in the same way.  The algorithm is to add
        // a computed amount of millis to the current millis.  The only
        // wrinkle is with DST -- for some fields, like the DAY_OF_MONTH,
        // we don't want the HOUR to shift due to changes in DST.  If the
        // result of the add operation is to move from DST to Standard, or
        // vice versa, we need to adjust by an hour forward or back,
        // respectively.  For such fields we set keepHourInvariant to TRUE.

        // We only adjust the DST for fields larger than an hour.  For
        // fields smaller than an hour, we cannot adjust for DST without
        // causing problems.  for instance, if you add one hour to April 5,
        // 1998, 1:00 AM, in PST, the time becomes "2:00 AM PDT" (an
        // illegal value), but then the adjustment sees the change and
        // compensates by subtracting an hour.  As a result the time
        // doesn't advance at all.

        // For some fields larger than a day, such as a UCAL_MONTH, we pin the
        // UCAL_DAY_OF_MONTH.  This allows <March 31>.add(UCAL_MONTH, 1) to be
        // <April 30>, rather than <April 31> => <May 1>.

        $delta = (float) $amount; // delta in ms
        $keepHourInvariant = true;

        switch ($field) {
            case DateDefinitions::ERA:

This code seems to be duplicated across your project.

                $this->set($field, $this->get($field) + $amount);
                $this->pinField(DateDefinitions::ERA);
                return;

            case DateDefinitions::YEAR:
            case DateDefinitions::EXTENDED_YEAR:
            case DateDefinitions::YEAR_WOY:
            case DateDefinitions::MONTH:

This code seems to be duplicated across your project.

                $this->set($field, $this->get($field) + $amount);
                $this->pinField(DateDefinitions::DAY_OF_MONTH);
                return;

            case DateDefinitions::WEEK_OF_YEAR:
            case DateDefinitions::WEEK_OF_MONTH:
            case DateDefinitions::DAY_OF_WEEK_IN_MONTH:
                $delta *= DateDefinitions::MILLIS_PER_WEEK;
                break;

            case DateDefinitions::AM_PM:
                $delta *= 12 * DateDefinitions::MILLIS_PER_HOUR;
                break;

            case DateDefinitions::DAY_OF_MONTH:
            case DateDefinitions::DAY_OF_YEAR:
            case DateDefinitions::DAY_OF_WEEK:
            case DateDefinitions::DOW_LOCAL:
            case DateDefinitions::JULIAN_DAY:
                $delta *= DateDefinitions::MILLIS_PER_DAY;
                break;

            case DateDefinitions::HOUR_OF_DAY:
            case DateDefinitions::HOUR:
                $delta *= DateDefinitions::MILLIS_PER_HOUR;
                $keepHourInvariant = false;
                break;

            case DateDefinitions::MINUTE:
                $delta *= DateDefinitions::MILLIS_PER_MINUTE;
                $keepHourInvariant = false;
                break;

            case DateDefinitions::SECOND:
                $delta *= DateDefinitions::MILLIS_PER_SECOND;
                $keepHourInvariant = false;
                break;

            case DateDefinitions::MILLISECOND:
            case DateDefinitions::MILLISECONDS_IN_DAY:
                $keepHourInvariant = false;
                break;

            default:
                throw new \InvalidArgumentException('Calendar::add(): field ' . $field . ' is not supported');
        }

        // In order to keep the hour invariant (for fields where this is
        // appropriate), record the DST_OFFSET before and after the add()
        // operation.  If it has changed, then adjust the millis to
        // compensate.
        $dst = 0;
        $hour = 0;
        if ($keepHourInvariant) {
            $dst = $this->get(DateDefinitions::DST_OFFSET);
            $hour = $this->internalGet(DateDefinitions::HOUR_OF_DAY);
        }

        $this->setTimeInMillis($this->getTimeInMillis() + $delta);

        if ($keepHourInvariant) {
            $dst -= $this->get(DateDefinitions::DST_OFFSET);
            if ($dst != 0) {
                // We have done an hour-invariant adjustment but the
                // DST offset has altered.  We adjust millis to keep
                // the hour constant.  In cases such as midnight after
                // a DST change which occurs at midnight, there is the
                // danger of adjusting into a different day.  To avoid
                // this we make the adjustment only if it actually
                // maintains the hour.

                /* double */
                $t = $this->internalGetTime();
                $this->setTimeInMillis($t + $dst);
                if ($this->get(DateDefinitions::HOUR_OF_DAY) != $hour) {
                    $this->setTimeInMillis($t);
                }
            }
        }
    }

    /**
     * Time Field Rolling function. Rolls by the given amount on the given
     * time field. For example, to roll the current date up by one day, call
     * roll(DateDefinitions::DATE, +1). When rolling on the month or
     * DateDefinitions::MONTH field, other fields like date might
     * conflict and, need to be changed. For instance, rolling the month up on the
     * date 01/31/96 will result in 02/29/96.  Rolling by a positive value always
     * means rolling forward in time; e.g., rolling the year by +1 on "100 BC"
     * will result in "99 BC", for Gregorian calendar. When rolling on the
     * hour-in-day or DateDefinitions::HOUR_OF_DAY field, it will
     * roll the hour value in the range between 0 and 23, which is zero-based.
     * <P>
     * The only difference between roll() and add() is that roll() does not change
     * the value of more significant fields when it reaches the minimum or maximum
     * of its range, whereas add() does.
     *
     * @param      int $field  The time field.
     * @param      int $amount Indicates amount to roll.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function roll($field, $amount)
    {
        // this is overloaded in c++ with roll($field, $up)
        if (is_bool($amount)) {
            $amount = $amount ? +1 : -1;
        }

        if ($amount == 0) {
            return; // Nothing to do
        }

        $this->complete();

        switch ($field) {
            case DateDefinitions::DAY_OF_MONTH:
            case DateDefinitions::AM_PM:
            case DateDefinitions::MINUTE:
            case DateDefinitions::SECOND:
            case DateDefinitions::MILLISECOND:
            case DateDefinitions::MILLISECONDS_IN_DAY:
            case DateDefinitions::ERA:

case statements should be defined using a colon.

                // These are the standard roll instructions.  These work for all
                // simple cases, that is, cases in which the limits are fixed, such
                // as the hour, the day of the month, and the era.
                {
                    $min = $this->getActualMinimum($field);
                    $max = $this->getActualMaximum($field);
                    $gap = $max - $min + 1;

                    $value = $this->internalGet($field) + $amount;
                    $value = ($value - $min) % $gap;
                if ($value < 0) {
                    $value += $gap;
                }
                    $value += $min;

                    $this->set($field, $value);
                return;
            }

            case DateDefinitions::HOUR:
            case DateDefinitions::HOUR_OF_DAY:

case statements should be defined using a colon.

                // Rolling the hour is difficult on the ONSET and CEASE days of
                // daylight savings.  For example, if the change occurs at
                // 2 AM, we have the following progression:
                // ONSET: 12 Std -> 1 Std -> 3 Dst -> 4 Dst
                // CEASE: 12 Dst -> 1 Dst -> 1 Std -> 2 Std
                // To get around this problem we don't use fields; we manipulate
                // the time in millis directly.
                {
                    // Assume min == 0 in calculations below
                    /* double */ $start = $this->getTimeInMillis();
                    $oldHour = $this->internalGet($field);
                    $max = $this->getMaximum($field);
                    $newHour = ($oldHour + $amount) % ($max + 1);
                if ($newHour < 0) {
                    $newHour += $max + 1;
                }
                    $this->setTimeInMillis($start + DateDefinitions::MILLIS_PER_HOUR * ($newHour - $oldHour));
                return;
            }

            case DateDefinitions::MONTH:

case statements should be defined using a colon.

                // Rolling the month involves both pinning the final value
                // and adjusting the DAY_OF_MONTH if necessary.  We only adjust the
                // DAY_OF_MONTH if, after updating the MONTH field, it is illegal.
                // E.g., <jan31>.roll(MONTH, 1) -> <feb28> or <feb29>.
                {
                        $max = $this->getActualMaximum(DateDefinitions::MONTH);
                        $mon = ($this->internalGet(DateDefinitions::MONTH) + $amount) % ($max + 1);

                if ($mon < 0) {
                    $mon += ($max + 1);
                }
                        $this->set(DateDefinitions::MONTH, $mon);

                        // Keep the day of month in range.  We don't want to spill over
                        // into the next month; e.g., we don't want jan31 + 1 mo -> feb31 ->
                        // mar3.
                        $this->pinField(DateDefinitions::DAY_OF_MONTH);
                return;
            }

            case DateDefinitions::YEAR:
            case DateDefinitions::YEAR_WOY:
            case DateDefinitions::EXTENDED_YEAR:

This code seems to be duplicated across your project.

                // Rolling the year can involve pinning the DAY_OF_MONTH.
                $this->set($field, $this->internalGet($field) + $amount);
                $this->pinField(DateDefinitions::MONTH);
                $this->pinField(DateDefinitions::DAY_OF_MONTH);
                return;

            case DateDefinitions::WEEK_OF_MONTH:

This code seems to be duplicated across your project.

case statements should be defined using a colon.

                {
                        // This is tricky, because during the roll we may have to shift
                        // to a different day of the week.  For example:

                        //    s  m  t  w  r  f  s
                        //          1  2  3  4  5

50% of this comment could be valid code. Did you maybe forget this after debugging?

                        //    6  7  8  9 10 11 12

50% of this comment could be valid code. Did you maybe forget this after debugging?

                        // When rolling from the 6th or 7th back one week, we go to the
                        // 1st (assuming that the first partial week counts).  The same
                        // thing happens at the end of the month.

                        // The other tricky thing is that we have to figure out whether
                        // the first partial week actually counts or not, based on the
                        // minimal first days in the week.  And we have to use the
                        // correct first day of the week to delineate the week
                        // boundaries.

                        // Here's our algorithm.  First, we find the real boundaries of
                        // the month.  Then we discard the first partial week if it
                        // doesn't count in this locale.  Then we fill in the ends with
                        // phantom days, so that the first partial week and the last
                        // partial week are full weeks.  We then have a nice square
                        // block of weeks.  We do the usual rolling within this block,
                        // as is done elsewhere in this method.  If we wind up on one of
                        // the phantom days that we added, we recognize this and pin to
                        // the first or the last day of the month.  Easy, eh?

                        // Normalize the DAY_OF_WEEK so that 0 is the first day of the week
                        // in this locale.  We have dow in 0..6.
                        $dow = $this->internalGet(DateDefinitions::DAY_OF_WEEK) - $this->getFirstDayOfWeek();
                if ($dow < 0) {
                    $dow += 7;
                }

                        // Find the day of the week (normalized for locale) for the first
                        // of the month.
                        $fdm = ($dow - $this->internalGet(DateDefinitions::DAY_OF_MONTH) + 1) % 7;
                if ($fdm < 0) {
                    $fdm += 7;
                }

                        // Get the first day of the first full week of the month,
                        // including phantom days, if any.  Figure out if the first week
                        // counts or not; if it counts, then fill in phantom days.  If
                        // not, advance to the first real full week (skip the partial week).
                if ((7 - $fdm) < $this->getMinimalDaysInFirstWeek()) {
                    $start = 8 - $fdm; // Skip the first partial week
                } else {
                    $start = 1 - $fdm; // This may be zero or negative
                }

                        // Get the day of the week (normalized for locale) for the last
                        // day of the month.
                        $monthLen = $this->getActualMaximum(DateDefinitions::DAY_OF_MONTH);
                        $ldm = ($monthLen - $this->internalGet(DateDefinitions::DAY_OF_MONTH) + $dow) % 7;
                        // We know monthLen >= DAY_OF_MONTH so we skip the += 7 step here.

                        // Get the limit day for the blocked-off rectangular month; that
                        // is, the day which is one past the last day of the month,
                        // after the month has already been filled in with phantom days
                        // to fill out the last week.  This day has a normalized DOW of 0.
                        $limit = $monthLen + 7 - $ldm;

                        // Now roll between start and (limit - 1).
                        $gap = $limit - $start;
                        $day_of_month = ($this->internalGet(DateDefinitions::DAY_OF_MONTH) + $amount * 7 - $start) % $gap;
                if ($day_of_month < 0) {
                    $day_of_month += $gap;
                }
                        $day_of_month += $start;

                        // Finally, pin to the real start and end of the month.
                if ($day_of_month < 1) {
                    $day_of_month = 1;
                }
                if ($day_of_month > $monthLen) {
                    $day_of_month = $monthLen;
                }

                        // Set the DAY_OF_MONTH.  We rely on the fact that this field
                        // takes precedence over everything else (since all other fields
                        // are also set at this point).  If this fact changes (if the
                        // disambiguation algorithm changes) then we will have to unset
                        // the appropriate fields here so that DAY_OF_MONTH is attended
                        // to.
                        $this->set(DateDefinitions::DAY_OF_MONTH, $day_of_month);
                return;
            }
            case DateDefinitions::WEEK_OF_YEAR:

This code seems to be duplicated across your project.

case statements should be defined using a colon.

                {
                    // This follows the outline of WEEK_OF_MONTH, except it applies
                    // to the whole year.  Please see the comment for WEEK_OF_MONTH
                    // for general notes.

                    // Normalize the DAY_OF_WEEK so that 0 is the first day of the week
                    // in this locale.  We have dow in 0..6.
                    $dow = $this->internalGet(DateDefinitions::DAY_OF_WEEK) - $this->getFirstDayOfWeek();
                if ($dow < 0) {
                    $dow += 7;
                }

                    // Find the day of the week (normalized for locale) for the first
                    // of the year.
                    $fdy = ($dow - $this->internalGet(DateDefinitions::DAY_OF_YEAR) + 1) % 7;
                if ($fdy < 0) {
                    $fdy += 7;
                }

                    // Get the first day of the first full week of the year,
                    // including phantom days, if any.  Figure out if the first week
                    // counts or not; if it counts, then fill in phantom days.  If
                    // not, advance to the first real full week (skip the partial week).
                if ((7 - $fdy) < $this->getMinimalDaysInFirstWeek()) {
                    $start = 8 - $fdy; // Skip the first partial week
                } else {
                    $start = 1 - $fdy; // This may be zero or negative
                }

                    // Get the day of the week (normalized for locale) for the last
                    // day of the year.
                    $yearLen = $this->getActualMaximum(DateDefinitions::DAY_OF_YEAR);
                    $ldy = ($yearLen - $this->internalGet(DateDefinitions::DAY_OF_YEAR) + $dow) % 7;
                    // We know yearLen >= DAY_OF_YEAR so we skip the += 7 step here.

                    // Get the limit day for the blocked-off rectangular year; that
                    // is, the day which is one past the last day of the year,
                    // after the year has already been filled in with phantom days
                    // to fill out the last week.  This day has a normalized DOW of 0.
                    $limit = $yearLen + 7 - $ldy;

                    // Now roll between start and (limit - 1).
                    $gap = $limit - $start;
                    $day_of_year = ($this->internalGet(DateDefinitions::DAY_OF_YEAR) + $amount * 7 - $start) % $gap;
                if ($day_of_year < 0) {
                    $day_of_year += $gap;
                }
                    $day_of_year += $start;

                    // Finally, pin to the real start and end of the month.
                if ($day_of_year < 1) {
                    $day_of_year = 1;
                }
                if ($day_of_year > $yearLen) {
                    $day_of_year = $yearLen;
                }

                    // Make sure that the year and day of year are attended to by
                    // clearing other fields which would normally take precedence.
                    // If the disambiguation algorithm is changed, this section will
                    // have to be updated as well.
                    $this->set(DateDefinitions::DAY_OF_YEAR, $day_of_year);
                    $this->clear(DateDefinitions::MONTH);
                return;
            }
            case DateDefinitions::DAY_OF_YEAR:

case statements should be defined using a colon.

                {
                    // Roll the day of year using millis.  Compute the millis for
                    // the start of the year, and get the length of the year.
                    $delta = (float) ($amount * DateDefinitions::MILLIS_PER_DAY); // Scale up from days to millis
                    $min2 = (float) ($this->internalGet(DateDefinitions::DAY_OF_YEAR) - 1);
                    $min2 *= DateDefinitions::MILLIS_PER_DAY;
                    $min2 = $this->internalGetTime() - $min2;

                    $yearLength = (float) $this->getActualMaximum(DateDefinitions::DAY_OF_YEAR);
                    $oneYear = $yearLength;
                    $oneYear *= DateDefinitions::MILLIS_PER_DAY;
                    $newtime = fmod(($this->internalGetTime() + $delta - $min2), $oneYear);
                if ($newtime < 0) {
                    $newtime += $oneYear;
                }
                    $this->setTimeInMillis($newtime + $min2);
                return;
            }
            case DateDefinitions::DAY_OF_WEEK:
            case DateDefinitions::DOW_LOCAL:

case statements should be defined using a colon.

                {
                    // Roll the day of week using millis.  Compute the millis for
                    // the start of the week, using the first day of week setting.
                    // Restrict the millis to [start, start+7days).
                    $delta = (float) ($amount * DateDefinitions::MILLIS_PER_DAY); // Scale up from days to millis
                    // Compute the number of days before the current day in this
                    // week.  This will be a value 0..6.
                    $leadDays = $this->internalGet($field);
                    $leadDays -= ($field == DateDefinitions::DAY_OF_WEEK) ? $this->getFirstDayOfWeek() : 1;
                if ($leadDays < 0) {
                    $leadDays += 7;
                }
                    $min2 = (float) ($this->internalGetTime() - $leadDays * DateDefinitions::MILLIS_PER_DAY);
                    $newtime = fmod(($this->internalGetTime() + $delta - $min2), DateDefinitions::MILLIS_PER_WEEK);
                if ($newtime < 0) {
                    $newtime += DateDefinitions::MILLIS_PER_WEEK;
                }
                    $this->setTimeInMillis($newtime + $min2);
                return;
            }
            case DateDefinitions::DAY_OF_WEEK_IN_MONTH:

case statements should be defined using a colon.

                {
                    // Roll the day of week in the month using millis.  Determine
                    // the first day of the week in the month, and then the last,
                    // and then roll within that range.
                    $delta = (float) ($amount * DateDefinitions::MILLIS_PER_WEEK); // Scale up from weeks to millis
                    // Find the number of same days of the week before this one
                    // in this month.
                    $preWeeks = (int) (($this->internalGet(DateDefinitions::DAY_OF_MONTH) - 1) / 7);
                    // Find the number of same days of the week after this one
                    // in this month.
                    $postWeeks = (int) (($this->getActualMaximum(DateDefinitions::DAY_OF_MONTH) - $this->internalGet(DateDefinitions::DAY_OF_MONTH)) / 7);
                    // From these compute the min and gap millis for rolling.
                    $min2 = (float) ($this->internalGetTime() - $preWeeks * DateDefinitions::MILLIS_PER_WEEK);
                    $gap2 = (float) (DateDefinitions::MILLIS_PER_WEEK * ($preWeeks + $postWeeks + 1)); // Must add 1!
                    // Roll within this range
                    $newtime = fmod(($this->internalGetTime() + $delta - $min2), $gap2);
                if ($newtime < 0) {
                    $newtime += $gap2;
                }
                    $this->setTimeInMillis($newtime + $min2);
                return;
            }
            case DateDefinitions::JULIAN_DAY:
                $this->set($field, $this->internalGet($field) + $amount);
                return;
            default:
                // Other fields cannot be rolled by this method
                throw new \InvalidArgumentException('Calendar::roll(): field ' . $field . ' cannot be rolled with this method');
        }
    }

    /**
     * Return the difference between the given time and the time this
     * calendar object is set to.  If this calendar is set
     * <em>before</em> the given time, the returned value will be
     * positive.  If this calendar is set <em>after</em> the given
     * time, the returned value will be negative.  The
     * <code>field</code> parameter specifies the units of the return
     * value.  For example, if <code>fieldDifference($when,
     * DateDefinitions::MONTH)</code> returns 3, then this calendar is set to
     * 3 months before <code>when</code>, and possibly some addition
     * time less than one month.
     *
     * <p>As a side effect of this call, this calendar is advanced
     * toward <code>$when</code> by the given amount.  That is, calling
     * this method has the side effect of calling <code>add($field,
     * $n)</code>, where <code>n</code> is the return value.
     *
     * <p>Usage: To use this method, call it first with the largest
     * field of interest, then with progressively smaller fields.  For
     * example:
     *
     * <pre>
     * $y = $cal->fieldDifference($when, DateDefinitions::YEAR);
     * $m = $cal->fieldDifference($when, DateDefinitions::MONTH);
     * $d = $cal->fieldDifference($when, DateDefinitions::DATE);</pre>
     *
     * computes the difference between <code>$cal</code> and
     * <code>$when</code> in years, months, and days.
     *
     * <p>Note: <code>fieldDifference()</code> is
     * <em>asymmetrical</em>.  That is, in the following code:
     *
     * <pre>
     * $cal->setTime($date1);
     * $m1 = $cal->fieldDifference($date2, DateDefinitions::MONTH);
     * $d1 = $cal->fieldDifference($date2, DateDefinitions::DATE);
     * $cal->setTime($date2);
     * $m2 = $cal->fieldDifference($date1, DateDefinitions::MONTH);
     * $d2 = $cal->fieldDifference($date1, DateDefinitions::DATE);</pre>
     *
     * one might expect that <code>$m1 == -$m2 && $d1 == -$d2</code>.
     * However, this is not generally the case, because of
     * irregularities in the underlying calendar system (e.g., the
     * Gregorian calendar has a varying number of days per month).
     *
     * @param      float|Calendar $targetMs When the date to compare this
     *                                      calendar's time to
     * @param      int            $field    The field in which to compute the result
     *
     * @return     int       The difference, either positive or negative, between
     *                       this calendar's time and <code>when</code>, in terms
     *                       of <code>field</code>.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function fieldDifference($targetMs /* $when */, $field)
    {
        $min = 0;
        $startMs = (float) $this->getTimeInMillis();
        if ($targetMs instanceof Calendar) {
            $targetMs = (float) $targetMs->getTimeInMillis();
        }
        // Always add from the start millis.  This accommodates
        // operations like adding years from February 29, 2000 up to
        // February 29, 2004.  If 1, 1, 1, 1 is added to the year

37% of this comment could be valid code. Did you maybe forget this after debugging?

        // field, the DOM gets pinned to 28 and stays there, giving an
        // incorrect DOM difference of 1.  We have to add 1, reset, 2,
        // reset, 3, reset, 4.

46% of this comment could be valid code. Did you maybe forget this after debugging?

        if ($startMs < $targetMs) {
            $max = 1;
            // Find a value that is too large
            while (true) {

This code seems to be duplicated across your project.

                $this->setTimeInMillis($startMs);
                $this->add($field, $max);
                $ms = (float) $this->getTimeInMillis();
                if ($ms == $targetMs) {
                    return $max;
                } elseif ($ms > $targetMs) {
                    break;
                } else {
                    $max <<= 1;
                    if ($max < 0) {
                        // TODO: check if we can change this to float to support a larger range
                        // Field difference too large to fit into int32_t
                        throw new \InvalidArgumentException('The difference is to large to fit into an integer');
                    }
                }
            }
            // Do a binary search
            while (($max - $min) > 1) {

This code seems to be duplicated across your project.

                $t = (int) (($min + $max) / 2);
                $this->setTimeInMillis($startMs);
                $this->add($field, $t);
                $ms = (float) $this->getTimeInMillis();
                if ($ms == $targetMs) {
                    return $t;
                } elseif ($ms > $targetMs) {
                    $max = $t;
                } else {
                    $min = $t;
                }
            }
        } elseif ($startMs > $targetMs) {
            $max = -1;
            // Find a value that is too small
            while (true) {

This code seems to be duplicated across your project.

                $this->setTimeInMillis($startMs);
                $this->add($field, $max);
                $ms = (float) $this->getTimeInMillis();
                if ($ms == $targetMs) {
                    return $max;
                } elseif ($ms < $targetMs) {
                    break;
                } else {
                    $max <<= 1;
                    if ($max == 0) {
                        // TODO: see above
                        // Field difference too large to fit into int32_t
                        throw new \InvalidArgumentException('The difference is to large to fit into an integer');
                    }
                }
            }
            // Do a binary search
            while (($min - $max) > 1) {

This code seems to be duplicated across your project.

                $t = (int) (($min + $max) / 2);
                $this->setTimeInMillis($startMs);
                $this->add($field, $t);
                $ms = (float) $this->getTimeInMillis();
                if ($ms == $targetMs) {
                    return $t;
                } elseif ($ms < $targetMs) {
                    $max = $t;
                } else {
                    $min = $t;
                }
            }
        }
        // Set calendar to end point
        $this->setTimeInMillis($startMs);
        $this->add($field, $min);

        return $min;
    }

    /**
     * Sets the calendar's time zone to be the same as the one passed in. The
     * TimeZone passed in is _not_ cloned.
     *
     * @param      TimeZone $zone The given time zone. If null is passed nothing
     *                            is done.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function setTimeZone(TimeZone $zone = null)
    {
        // Do nothing if passed-in zone is NULL
        if (!$zone) {
            return;
        }

        // fZone should always be non-null
        $this->fZone = $zone;

        // if the zone changes, we need to recompute the time fields
        $this->fAreFieldsInSync = false;
    }

    /**
     * Returns a reference to the time zone owned by this calendar.
     *
     * @return     TimeZone The time zone object associated with this
     *                           calendar.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getTimeZone()
    {
        return $this->fZone;
    }

    /**
     * Queries if the current date for this Calendar is in Daylight Savings Time.
     *
     * @return     bool True if the current date for this Calendar is in
     *                  Daylight Savings Time, false, otherwise.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract public function inDaylightTime();

    /**
     * Specifies whether or not date/time interpretation is to be lenient. With
     * lenient interpretation, a date such as "February 942, 1996" will be treated
     * as being equivalent to the 941st day after February 1, 1996. With strict
     * interpretation, such dates will cause an error when computing time from the
     * time field values representing the dates.
     *
     * @param      bool $lenient True specifies date/time interpretation to be lenient.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function setLenient($lenient)
    {
        $this->fLenient = $lenient;
    }

    /**
     * Tells whether date/time interpretation is to be lenient.
     *
     * @return     bool True tells that date/time interpretation is to be lenient.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function isLenient()
    {
        return $this->fLenient;
    }

    /**
     * Sets what the first day of the week is; e.g., Sunday in US, Monday in
     * France.
     *
     * @param      int $value The given first day of the week.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function setFirstDayOfWeek($value)
    {
        $this->fFirstDayOfWeek = $value;
    }

    /**
     * Gets what the first day of the week is; e.g., Sunday in US, Monday in
     * France.
     *
     * @return     int The first day of the week.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getFirstDayOfWeek()
    {
        return $this->fFirstDayOfWeek;
    }

    /**
     * Sets what the minimal days required in the first week of the year are; For
     * example, if the first week is defined as one that contains the first day of
     * the first month of a year, call the method with value 1. If it must be a
     * full week, use value 7.
     *
     * @param      int $value The given minimal days required in the first week of the
     *                 year.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function setMinimalDaysInFirstWeek($value)
    {
        $this->fMinimalDaysInFirstWeek = $value;
    }

    /**
     * Gets what the minimal days required in the first week of the year are;
     * e.g., if the first week is defined as one that contains the first day of
     * the first month of a year, getMinimalDaysInFirstWeek returns 1. If the
     * minimal days required must be a full week, getMinimalDaysInFirstWeek
     * returns 7.
     *
     * @return     int The minimal days required in the first week of the year.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getMinimalDaysInFirstWeek()
    {
        return $this->fMinimalDaysInFirstWeek;
    }

    /**
     * Gets the minimum value for the given time field. e.g., for Gregorian
     * DAY_OF_MONTH, 1.
     *
     * @param      int    $field The given time field.
     *
     * @return     int    The minimum value for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getMinimum($field)
    {
        return $this->getLimit($field, self::LIMIT_MINIMUM);
    }

    /**
     * Gets the maximum value for the given time field. e.g., for Gregorian
     * DAY_OF_MONTH, 31.
     *
     * @param      int    $field The given time field.
     *
     * @return     int    The maximum value for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getMaximum($field)
    {
        return $this->getLimit($field, self::LIMIT_MAXIMUM);
    }

    /**
     * Gets the highest minimum value for the given field if varies. Otherwise
     * same as getMinimum(). For Gregorian, no difference.
     *
     * @param      int    $field The given time field.
     *
     * @return     int    The highest minimum value for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getGreatestMinimum($field)
    {
        return $this->getLimit($field, self::LIMIT_GREATEST_MINIMUM);
    }

    /**
     * Gets the lowest maximum value for the given field if varies. Otherwise same
     * as getMaximum(). e.g., for Gregorian DAY_OF_MONTH, 28.
     *
     * @param      int    $field The given time field.
     *
     * @return     int    The lowest maximum value for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getLeastMaximum($field)
    {
        return $this->getLimit($field, self::LIMIT_LEAST_MAXIMUM);
    }

    /**
     * Return the minimum value that this field could have, given the current
     * date. For the Gregorian calendar, this is the same as getMinimum() and
     * getGreatestMinimum().
     *
     * The version of this function on Calendar uses an iterative algorithm to
     * determine the actual minimum value for the field.  There is almost always a
     * more efficient way to accomplish this (in most cases, you can simply return
     * getMinimum()).  GregorianCalendar overrides this function with a more
     * efficient implementation.
     *
     * @param      int    $field the field to determine the minimum of
     *
     * @return     int    the minimum of the given field for the current date of
     *                    this Calendar
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getActualMinimum($field)
    {
        $fieldValue = $this->getGreatestMinimum($field);
        $endValue = $this->getMinimum($field);

        // if we know that the minimum value is always the same, just return it
        if ($fieldValue == $endValue) {
            return $fieldValue;
        }

        // clone the calendar so we don't mess with the real one, and set it to
        // accept anything for the field values
        $work = clone $this;
        $work->setLenient(true);

        // now try each value from getLeastMaximum() to getMaximum() one by one until
        // we get a value that normalizes to another value.	 The last value that
        // normalizes to itself is the actual minimum for the current date
        $result = $fieldValue;

        do {

This code seems to be duplicated across your project.

            $work->set($field, $fieldValue);
            if ($work->get($field) != $fieldValue) {
                break;
            } else {
                $result = $fieldValue;
                $fieldValue--;
            }
        } while ($fieldValue >= $endValue);

        return $result;
    }

    /**
     * Return the maximum value that this field could have, given the current
     * date. For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field,
     * the actual maximum would be 28; for "Feb 3, 1996" it s 29.  Similarly for a
     * Hebrew calendar,for some years the actual maximum for MONTH is 12, and for
     * others 13.
     *
     * The version of this function on Calendar uses an iterative algorithm to
     * determine the actual maximum value for the field.  There is almost always a
     * more efficient way to accomplish this (in most cases, you can simply return
     * getMaximum()). AgaviGregorianCalendar overrides this function with a more
     * efficient implementation.
     *
     * @param      int    $field the field to determine the maximum of
     *
     * @return     int    the maximum of the given field for the current date of
     *                    this Calendar
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getActualMaximum($field)
    {
        switch ($field) {
            case DateDefinitions::DATE:

This code seems to be duplicated across your project.

                $cal = clone $this;
                $cal->prepareGetActual($field, false);
                $result = $this->handleGetMonthLength($cal->get(DateDefinitions::EXTENDED_YEAR), $cal->get(DateDefinitions::MONTH));
                break;

            case DateDefinitions::DAY_OF_YEAR:

This code seems to be duplicated across your project.

                $cal = clone $this;
                $cal->prepareGetActual($field, false);
                $result = $this->handleGetYearLength($cal->get(DateDefinitions::EXTENDED_YEAR));
                break;

            case DateDefinitions::DAY_OF_WEEK:
            case DateDefinitions::AM_PM:
            case DateDefinitions::HOUR:
            case DateDefinitions::HOUR_OF_DAY:
            case DateDefinitions::MINUTE:
            case DateDefinitions::SECOND:
            case DateDefinitions::MILLISECOND:
            case DateDefinitions::ZONE_OFFSET:
            case DateDefinitions::DST_OFFSET:
            case DateDefinitions::DOW_LOCAL:
            case DateDefinitions::JULIAN_DAY:
            case DateDefinitions::MILLISECONDS_IN_DAY:
                // These fields all have fixed minima/maxima
                $result = $this->getMaximum($field);
                break;

            default:
                // For all other fields, do it the hard way....
                $result = $this->getActualHelper($field, $this->getLeastMaximum($field), $this->getMaximum($field));
                break;
        }
        return $result;
    }

    /**
     * Gets all time field values. Recalculate the current time field
     * values if the time value has been changed by a call to setTime(). Return
     * zero for unset fields if any fields have been explicitly set by a call to
     * set(). To force a recomputation of all fields regardless of the previous
     * state, call complete().
     *
     * @return     array All fields of this instance.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function getAll()
    {
        // field values are only computed when actually requested; for more on when computation
        // of various things happens, see the "data flow in Calendar" description at the top
        // of this file
        $this->complete();
        return $this->fFields;
    }

    /**
     * Gets the value for a given time field. Recalculate the current time field
     * values if the time value has been changed by a call to setTime(). Return
     * zero for unset fields if any fields have been explicitly set by a call to
     * set(). To force a recomputation of all fields regardless of the previous
     * state, call complete().
     *
     * @param      int    $field The given time field.
     *
     * @return     int    The value for the given time field, or zero if the field
     *                    is unset, and set() has been called for any other field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function get($field)
    {
        // field values are only computed when actually requested; for more on when computation
        // of various things happens, see the "data flow in Calendar" description at the top
        // of this file
        $this->complete();
        return $this->fFields[$field];
    }

    /**
     * Determines if the given time field has a value set. This can affect in the
     * resolving of time in Calendar. Unset fields have a value of zero, by
     * definition.
     *
     * @param      int    $field The given time field.
     *
     * @return     bool   True if the given time field has a value set; false
     *                    otherwise.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function _isSet($field) // isset is a keyword in php
    {
        return $this->fAreFieldsVirtuallySet || ($this->fStamp[$field] != self::kUnset);
    }

    /**
     * Overloaded
     *
     * @see        Calendar::set1()
     * @see        Calendar::set2()
     * @see        Calendar::set3()
     * @see        Calendar::set4()
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function set()
    {
        $arguments = func_get_args();

        $fName = Toolkit::overloadHelper(array(
            array('name' => 'set1',
                        'parameters' => array('int', 'int')),
            array('name' => 'set2',
                        'parameters' => array('int', 'int', 'int')),
            array('name' => 'set3',
                        'parameters' => array('int', 'int', 'int', 'int', 'int')),
            array('name' => 'set4',
                        'parameters' => array('int', 'int', 'int', 'int', 'int', 'int')),
            ),
            $arguments
        );
        call_user_func_array(array($this, $fName), $arguments);
    }

    /**
     * Sets the given time field with the given value.
     *
     * @param      int    $field The given time field.
     * @param      int    $value The value to be set for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function set1($field, $value)

This method seems to be duplicated in your project.

    {
        if ($this->fAreFieldsVirtuallySet) {
            $this->computeFields();
        }

        $this->fFields[$field]    = $value;
        $this->fStamp[$field]     = $this->fNextStamp++;
        $this->fIsSet[$field]     = true; // Remove later

The property Agavi\Date\Calendar::$fIsSet has been deprecated with message: ICU 2.8 use (fStamp[n]!=kUnset)

        $this->fIsTimeSet = $this->fAreFieldsInSync = $this->fAreFieldsVirtuallySet = false;
    }

    /**
     * Sets the values for the fields YEAR, MONTH, and DATE. Other field values
     * are retained; call clear() first if this is not desired.
     *
     * @param      int $year  The value used to set the YEAR time field.
     * @param      int $month The value used to set the MONTH time field. Month value is
     *                        0-based. e.g., 0 for January.
     * @param      int $date  The value used to set the DATE time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function set2($year, $month, $date)
    {
        $this->set1(DateDefinitions::YEAR, $year);
        $this->set1(DateDefinitions::MONTH, $month);
        $this->set1(DateDefinitions::DATE, $date);
    }

    /**
     * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, and MINUTE.
     * Other field values are retained; call
     * ) first if this is not desired.
     *
     * @param      int $year   The value used to set the YEAR time field.
     * @param      int $month  The value used to set the MONTH time field. Month value is
     *                         0-based. E.g., 0 for January.
     * @param      int $date   The value used to set the DATE time field.
     * @param      int $hour   The value used to set the HOUR_OF_DAY time field.
     * @param      int $minute The value used to set the MINUTE time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function set3($year, $month, $date, $hour, $minute)

This method seems to be duplicated in your project.

    {
        $this->set1(DateDefinitions::YEAR, $year);
        $this->set1(DateDefinitions::MONTH, $month);
        $this->set1(DateDefinitions::DATE, $date);
        $this->set1(DateDefinitions::HOUR_OF_DAY, $hour);
        $this->set1(DateDefinitions::MINUTE, $minute);
    }

    /**
     * Sets the values for the fields YEAR, MONTH, DATE, HOUR_OF_DAY, MINUTE, and
     * SECOND. Other field values are retained; call clear() first if this is not
     * desired.
     *
     * @param      int $year   The value used to set the YEAR time field.
     * @param      int $month  The value used to set the MONTH time field. Month value is
     *                         0-based. E.g., 0 for January.
     * @param      int $date   The value used to set the DATE time field.
     * @param      int $hour   The value used to set the HOUR_OF_DAY time field.
     * @param      int $minute The value used to set the MINUTE time field.
     * @param      int $second The value used to set the SECOND time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function set4($year, $month, $date, $hour, $minute, $second)

This method seems to be duplicated in your project.

    {
        $this->set1(DateDefinitions::YEAR, $year);
        $this->set1(DateDefinitions::MONTH, $month);
        $this->set1(DateDefinitions::DATE, $date);
        $this->set1(DateDefinitions::HOUR_OF_DAY, $hour);
        $this->set1(DateDefinitions::MINUTE, $minute);
        $this->set1(DateDefinitions::SECOND, $second);
    }

    /**
     * Overloaded
     *
     * @see        Calendar::clear1()
     * @see        Calendar::clear2()
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function clear()
    {
        $arguments = func_get_args();

        $fName = Toolkit::overloadHelper(array(
            array('name' => 'clear1',
                        'parameters' => array()),
            array('name' => 'clear2',
                        'parameters' => array('int')),
            ),
            $arguments
        );
        call_user_func_array(array($this, $fName), $arguments);
    }

    /**
     * Clears the values of all the time fields, making them both unset and
     * assigning them a value of zero. The field values will be determined during
     * the next resolving of time into time fields.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function clear1()
    {
        for ($i = 0; $i < DateDefinitions::FIELD_COUNT; ++$i) {
            $this->fFields[$i]     = 0; // Must do this; other code depends on it
            $this->fStamp[$i]      = self::kUnset;
            $this->fIsSet[$i]      = false; // Remove later

The property Agavi\Date\Calendar::$fIsSet has been deprecated with message: ICU 2.8 use (fStamp[n]!=kUnset)

        }
        $this->fIsTimeSet = $this->fAreFieldsInSync = $this->fAreAllFieldsSet = $this->fAreFieldsVirtuallySet = false;
        // fTime is not 'cleared' - may be used if no fields are set.
    }

    /**
     * Clears the value in the given time field, both making it unset and
     * assigning it a value of zero. This field value will be determined during
     * the next resolving of time into time fields.
     *
     * @param      string $field The time field to be cleared.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    public function clear2($field)

This method seems to be duplicated in your project.

    {
        if ($this->fAreFieldsVirtuallySet) {
            $this->computeFields();
        }
        $this->fFields[$field]        = 0;
        $this->fStamp[$field]         = self::kUnset;
        $this->fIsSet[$field]         = false; // Remove later

The property Agavi\Date\Calendar::$fIsSet has been deprecated with message: ICU 2.8 use (fStamp[n]!=kUnset)

        $this->fIsTimeSet = $this->fAreFieldsInSync = $this->fAreAllFieldsSet = $this->fAreFieldsVirtuallySet = false;
    }

    /**
     * Converts Calendar's time field values to GMT as milliseconds.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function computeTime()
    {
        if (!$this->isLenient()) {
            $this->validateFields();
        }

        // Compute the Julian day
        $julianDay = $this->computeJulianDay();

        $millis = CalendarGrego::julianDayToMillis($julianDay);

        $millisInDay = 0;

$millisInDay is not used, you could remove the assignment.

        // We only use MILLISECONDS_IN_DAY if it has been set by the user.
        // This makes it possible for the caller to set the calendar to a
        // time and call clear(MONTH) to reset the MONTH to January.  This
        // is legacy behavior.  Without this, clear(MONTH) has no effect,
        // since the internally set JULIAN_DAY is used.
        if ($this->fStamp[DateDefinitions::MILLISECONDS_IN_DAY] >= (self::kMinimumUserStamp) &&
                $this->newestStamp(DateDefinitions::AM_PM, DateDefinitions::MILLISECOND, self::kUnset) <= $this->fStamp[DateDefinitions::MILLISECONDS_IN_DAY]) {
            $millisInDay = $this->internalGet(DateDefinitions::MILLISECONDS_IN_DAY);
        } else {
            $millisInDay = $this->computeMillisInDay();
        }

        // Compute the time zone offset and DST offset.  There are two potential
        // ambiguities here.  We'll assume a 2:00 am (wall time) switchover time
        // for discussion purposes here.
        // 1. The transition into DST.  Here, a designated time of 2:00 am - 2:59 am
        //    can be in standard or in DST depending.  However, 2:00 am is an invalid
        //    representation (the representation jumps from 1:59:59 am Std to 3:00:00 am DST).
        //    We assume standard time.
        // 2. The transition out of DST.  Here, a designated time of 1:00 am - 1:59 am
        //    can be in standard or DST.  Both are valid representations (the rep
        //    jumps from 1:59:59 DST to 1:00:00 Std).

46% of this comment could be valid code. Did you maybe forget this after debugging?

        //    Again, we assume standard time.
        // We use the TimeZone object, unless the user has explicitly set the ZONE_OFFSET
        // or DST_OFFSET fields; then we use those fields.
        if ($this->fStamp[DateDefinitions::ZONE_OFFSET] >= (self::kMinimumUserStamp) ||
                $this->fStamp[DateDefinitions::DST_OFFSET] >= (self::kMinimumUserStamp)) {
            $millisInDay -= $this->internalGet(DateDefinitions::ZONE_OFFSET) + $this->internalGet(DateDefinitions::DST_OFFSET);
        } else {
            $millisInDay -= $this->computeZoneOffset($millis, $millisInDay);
        }

        $this->internalSetTime($millis + $millisInDay);
    }

    /**
     * Converts GMT as milliseconds to time field values. This allows you to sync
     * up the time field values with a new time that is set for the calendar.
     * This method does NOT recompute the time first; to recompute the time, then
     * the fields, use the method complete().
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function computeFields()
    {
        // Compute local wall millis
        $localMillis = $this->internalGetTime();

        $rawOffset = $dstOffset = 0;
        $this->getTimeZone()->getOffsetRef($localMillis, false, $rawOffset, $dstOffset);
        $localMillis += $rawOffset;

        // Mark fields as set.  Do this before calling handleComputeFields().
        $mask =   //fInternalSetMask;
            (1 << DateDefinitions::ERA) |
            (1 << DateDefinitions::YEAR) |
            (1 << DateDefinitions::MONTH) |
            (1 << DateDefinitions::DAY_OF_MONTH) | // = UCAL_DATE
            (1 << DateDefinitions::DAY_OF_YEAR) |
            (1 << DateDefinitions::EXTENDED_YEAR);

        for ($i = 0; $i < DateDefinitions::FIELD_COUNT; ++$i) {
            if (($mask & 1) == 0) {
                $this->fStamp[$i] = self::kInternallySet;
                $this->fIsSet[$i] = true; // Remove later

The property Agavi\Date\Calendar::$fIsSet has been deprecated with message: ICU 2.8 use (fStamp[n]!=kUnset)

            } else {
                $this->fStamp[$i] = self::kUnset;
                $this->fIsSet[$i] = false; // Remove later

The property Agavi\Date\Calendar::$fIsSet has been deprecated with message: ICU 2.8 use (fStamp[n]!=kUnset)

            }
            $mask >>= 1;
        }

        // We used to check for and correct extreme millis values (near
        // Long.MIN_VALUE or Long.MAX_VALUE) here.  Such values would cause
        // overflows from positive to negative (or vice versa) and had to
        // be manually tweaked.  We no longer need to do this because we
        // have limited the range of supported dates to those that have a
        // Julian day that fits into an int.  This allows us to implement a
        // JULIAN_DAY field and also removes some inelegant code. - Liu
        // 11/6/00

50% of this comment could be valid code. Did you maybe forget this after debugging?

        $days = floor($localMillis / DateDefinitions::MILLIS_PER_DAY);

        $this->internalSet(DateDefinitions::JULIAN_DAY, $days + DateDefinitions::EPOCH_START_AS_JULIAN_DAY);

        // In some cases we will have to call this method again below to
        // adjust for DST pushing us into the next Julian day.
        $this->computeGregorianAndDOWFields($this->fFields[DateDefinitions::JULIAN_DAY]);

        $millisInDay =  (int) ($localMillis - ($days * DateDefinitions::MILLIS_PER_DAY));
        if ($millisInDay < 0) {
            $millisInDay += (int) DateDefinitions::MILLIS_PER_DAY;
        }

        // Adjust our millisInDay for DST.  dstOffset will be zero if DST
        // is not in effect at this time of year, or if our zone does not
        // use DST.
        $millisInDay += $dstOffset;

        // If DST has pushed us into the next day, we must call
        // computeGregorianAndDOWFields() again.  This happens in DST between
        // 12:00 am and 1:00 am every day.  The first call to
        // computeGregorianAndDOWFields() will give the wrong day, since the
        // Standard time is in the previous day.
        if ($millisInDay >= (int) DateDefinitions::MILLIS_PER_DAY) {
            $millisInDay -= (int) DateDefinitions::MILLIS_PER_DAY; // ASSUME dstOffset < 24:00

            // We don't worry about overflow of JULIAN_DAY because the
            // allowable range of JULIAN_DAY has slop at the ends (that is,
            // the max is less that 0x7FFFFFFF and the min is greater than
            // -0x80000000).
            $this->computeGregorianAndDOWFields(++$this->fFields[DateDefinitions::JULIAN_DAY]);
        }

        // Call framework method to have subclass compute its fields.
        // These must include, at a minimum, MONTH, DAY_OF_MONTH,
        // EXTENDED_YEAR, YEAR, DAY_OF_YEAR.  This method will call internalSet(),
        // which will update stamp[].
        $this->handleComputeFields($this->fFields[DateDefinitions::JULIAN_DAY]);

        // Compute week-related fields, based on the subclass-computed
        // fields computed by handleComputeFields().
        $this->computeWeekFields();

        // Compute time-related fields.  These are independent of the date and
        // of the subclass algorithm.  They depend only on the local zone
        // wall milliseconds in day.
        $this->fFields[DateDefinitions::MILLISECONDS_IN_DAY] = $millisInDay;
        $this->fFields[DateDefinitions::MILLISECOND] = $millisInDay % 1000;
        $millisInDay /= 1000;
        $this->fFields[DateDefinitions::SECOND] = $millisInDay % 60;
        $millisInDay /= 60;
        $this->fFields[DateDefinitions::MINUTE] = $millisInDay % 60;
        $millisInDay /= 60;
        $this->fFields[DateDefinitions::HOUR_OF_DAY] = (int) $millisInDay;
        $this->fFields[DateDefinitions::AM_PM] = (int) ($millisInDay / 12); // Assume AM == 0
        $this->fFields[DateDefinitions::HOUR] = $millisInDay % 12;
        $this->fFields[DateDefinitions::ZONE_OFFSET] = $rawOffset;
        $this->fFields[DateDefinitions::DST_OFFSET] = $dstOffset;
    }

    /**
     * Gets this Calendar's current time as a long.
     *
     * @return     double the current time as UTC milliseconds from the epoch.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getTimeInMillis()
    {
        if (!$this->fIsTimeSet) {
            $this->updateTime();
        }

        return $this->fTime;
    }

    /**
     * Sets this Calendar's current time from the given long value.
     *
     * @param      double $millis the new time in UTC milliseconds from the epoch.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function setTimeInMillis($millis)
    {
        $millis = (float) $millis;
        
        if ($millis > self::MAX_MILLIS) {
            $millis = self::MAX_MILLIS;
        } elseif ($millis < self::MIN_MILLIS) {
            $millis = self::MIN_MILLIS;
        }

        $this->fTime = $millis;

It seems like $millis can also be of type integer. However, the property $fTime is declared as type double. Maybe add an additional type check?

        $this->fAreFieldsInSync = $this->fAreAllFieldsSet = false;
        $this->fIsTimeSet = $this->fAreFieldsVirtuallySet = true;
    }

    /**
     * Recomputes the current time from currently set fields, and then fills in
     * any unset fields in the time field list.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function complete()
    {
        if (!$this->fIsTimeSet) {
            $this->updateTime();
        }

        if (!$this->fAreFieldsInSync) {
            $this->computeFields(); // fills in unset fields

            $this->fAreFieldsInSync        = true;
            $this->fAreAllFieldsSet     = true;
        }
    }

    /**
     * Gets the value for a given time field. Subclasses can use this function to
     * get field values without forcing recomputation of time. If the field's
     * stamp is UNSET, the defaultValue is used.
     *
     * @param      int    $field        The given time field.
     * @param      int    $defaultValue a default value used if the field is unset.
     * @return     int    The value for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function internalGet($field, $defaultValue = null)
    {
        return $this->fStamp[$field] > self::kUnset ? $this->fFields[$field] : $defaultValue;
    }

    /**
     * Sets the value for a given time field.  This is a fast internal method for
     * subclasses.  It does not affect the fAreFieldsInSync, isTimeSet, or
     * areAllFieldsSet flags.
     *
     * @param      int    $field The given time field.
     * @param      int    $value The value for the given time field.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function internalSet($field, $value)
    {
        $this->fFields[$field]  = $value;
        $this->fStamp[$field]   = self::kInternallySet;
        $this->fIsSet[$field]   = true; // Remove later

The property Agavi\Date\Calendar::$fIsSet has been deprecated with message: ICU 2.8 use (fStamp[n]!=kUnset)

    }

    /**
     * Prepare this calendar for computing the actual minimum or maximum.
     * This method modifies this calendar's fields; it is called on a
     * temporary calendar.
     *
     * @param      int   $field     The given time field
     * @param      bool  $isMinimum
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function prepareGetActual($field, $isMinimum)
    {
        $this->set(DateDefinitions::MILLISECONDS_IN_DAY, 0);

        switch ($field) {
            case DateDefinitions::YEAR:
            case DateDefinitions::YEAR_WOY:
            case DateDefinitions::EXTENDED_YEAR:
                $this->set(DateDefinitions::DAY_OF_YEAR, $this->getGreatestMinimum(DateDefinitions::DAY_OF_YEAR));
                break;

            case DateDefinitions::MONTH:
                $this->set(DateDefinitions::DATE, $this->getGreatestMinimum(DateDefinitions::DATE));
                break;

            case DateDefinitions::DAY_OF_WEEK_IN_MONTH:
                // For dowim, the maximum occurs for the DOW of the first of the
                // month.
                $this->set(DateDefinitions::DATE, 1);
                $this->set(DateDefinitions::DAY_OF_WEEK, $this->get(DateDefinitions::DAY_OF_WEEK)); // Make this user set
                break;

            case DateDefinitions::WEEK_OF_MONTH:
            case DateDefinitions::WEEK_OF_YEAR:
                // If we're counting weeks, set the day of the week to either the
                // first or last localized DOW.  We know the last week of a month
                // or year will contain the first day of the week, and that the
                // first week will contain the last DOW.
                $dow = $this->fFirstDayOfWeek;
                if ($isMinimum) {
                    $dow = ($dow + 6) % 7; // set to last DOW
                    if ($dow < DateDefinitions::SUNDAY) {
                        $dow += 7;
                    }
                }

                $this->set(DateDefinitions::DAY_OF_WEEK, $dow);
                break;
            default:
                ;
        }

        // Do this last to give it the newest time stamp
        $this->set($field, $this->getGreatestMinimum($field));
    }

    /**
     * Subclass API for defining limits of different types.
     * Subclasses must implement this method to return limits for the
     * following fields:
     *
     * <pre>DateDefinitions::ERA
     * DateDefinitions::YEAR
     * DateDefinitions::MONTH
     * DateDefinitions::WEEK_OF_YEAR
     * DateDefinitions::WEEK_OF_MONTH
     * DateDefinitions::DATE
     * DateDefinitions::DAY_OF_YEAR
     * DateDefinitions::DAY_OF_WEEK_IN_MONTH
     * DateDefinitions::YEAR_WOY
     * DateDefinitions::EXTENDED_YEAR</pre>
     *
     * @param      int $field     one of the above field numbers
     * @param      int $limitType one of <code>self::LIMIT_MINIMUM</code>,
     *                            <code>self::LIMIT_GREATEST_MINIMUM</code>,
     *                            <code>self::LIMIT_LEAST_MAXIMUM</code>,
     *                            or <code>self::LIMIT_MAXIMUM</code>
     *
     * @return     int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract protected function handleGetLimit($field, $limitType);

    /**
     * Return a limit for a field.
     *
     * @param      int $field     the field
     * @param      int $limitType the type specifier for the limit
     *
     * @return     int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getLimit($field, $limitType)
    {
        switch ($field) {
            case DateDefinitions::DAY_OF_WEEK:
            case DateDefinitions::AM_PM:
            case DateDefinitions::HOUR:
            case DateDefinitions::HOUR_OF_DAY:
            case DateDefinitions::MINUTE:
            case DateDefinitions::SECOND:
            case DateDefinitions::MILLISECOND:
            case DateDefinitions::ZONE_OFFSET:
            case DateDefinitions::DST_OFFSET:
            case DateDefinitions::DOW_LOCAL:
            case DateDefinitions::JULIAN_DAY:
            case DateDefinitions::MILLISECONDS_IN_DAY:
                return self::$kCalendarLimits[$field][$limitType];
            default:
                return $this->handleGetLimit($field, $limitType);
        }
    }

    /**
     * Return the Julian day number of day before the first day of the
     * given month in the given extended year.  Subclasses should override
     * this method to implement their calendar system.
     *
     * @param      int  $eyear the extended year
     * @param      int  $month the zero-based month, or 0 if useMonth is false
     * @param      bool $useMonth if false, compute the day before the first day of
     *                  the given year, otherwise, compute the day before the
     *                  first day of the given month
     *
     * @return     int  the Julian day number of the day before the first
     *                  day of the given month and year
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract protected function handleComputeMonthStart($eyear, $month, $useMonth);

    /**
     * Return the number of days in the given month of the given extended
     * year of this calendar system.  Subclasses should override this
     * method if they can provide a more correct or more efficient
     * implementation than the default implementation in Calendar.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function handleGetMonthLength($extendedYear, $month)
    {
        return $this->handleComputeMonthStart($extendedYear, $month + 1, true) -
                        $this->handleComputeMonthStart($extendedYear, $month, true);
    }

    /**
     * Return the number of days in the given extended year of this
     * calendar system.  Subclasses should override this method if they can
     * provide a more correct or more efficient implementation than the
     * default implementation in Calendar.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function handleGetYearLength($eyear)
    {
        return $this->handleComputeMonthStart($eyear + 1, 0, false) -
                        $this->handleComputeMonthStart($eyear, 0, false);
    }

    /**
     * Return the extended year defined by the current fields.  This will
     * use the EXTENDED_YEAR field or the YEAR and supra-year fields
     * (such as ERA) specific to the calendar system, depending on which set
     * of fields is newer.
     *
     * @return     int the extended year
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract protected function handleGetExtendedYear();

    /**
     * Subclasses may override this.  This method calls
     * handleGetMonthLength() to obtain the calendar-specific month
     * length.
     *
     * @param      string $bestField which field to use to calculate the date
     *
     * @return     int    julian day specified by calendar fields.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function handleComputeJulianDay($bestField)
    {
        $useMonth = ($bestField == DateDefinitions::DAY_OF_MONTH ||
                                    $bestField == DateDefinitions::WEEK_OF_MONTH ||
                                    $bestField == DateDefinitions::DAY_OF_WEEK_IN_MONTH);
        $year = 0;

$year is not used, you could remove the assignment.

        if ($bestField == DateDefinitions::WEEK_OF_YEAR) {
            $year = $this->internalGet(DateDefinitions::YEAR_WOY, $this->handleGetExtendedYear());
            $this->internalSet(DateDefinitions::EXTENDED_YEAR, $year);
        } else {
            $year = $this->handleGetExtendedYear();
            $this->internalSet(DateDefinitions::EXTENDED_YEAR, $year);
        }

        // Get the Julian day of the day BEFORE the start of this year.
        // If useMonth is true, get the day before the start of the month.

        // give calendar subclass a chance to have a default 'first' month
        $month = 0;

$month is not used, you could remove the assignment.

        if ($this->_isSet(DateDefinitions::MONTH)) {
            $month = $this->internalGet(DateDefinitions::MONTH);
        } else {
            $month = $this->getDefaultMonthInYear();
        }

        $julianDay = $this->handleComputeMonthStart($year, $useMonth ? $month : 0, $useMonth);

        if ($bestField == DateDefinitions::DAY_OF_MONTH) {
            // give calendar subclass a chance to have a default 'first' dom
            $dayOfMonth = 0;

$dayOfMonth is not used, you could remove the assignment.

            if ($this->_isSet(DateDefinitions::DAY_OF_MONTH)) {
                $dayOfMonth = $this->internalGet(DateDefinitions::DAY_OF_MONTH, 1);
            } else {
                $dayOfMonth = $this->getDefaultDayInMonth($month);
            }

            return $julianDay + $dayOfMonth;
        }

        if ($bestField == DateDefinitions::DAY_OF_YEAR) {
            return $julianDay + $this->internalGet(DateDefinitions::DAY_OF_YEAR);
        }

        $firstDayOfWeek = $this->getFirstDayOfWeek(); // Localized fdw

        // At this point julianDay is the 0-based day BEFORE the first day of
        // January 1, year 1 of the given calendar.  If julianDay == 0, it
        // specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
        // or Gregorian). (or it is before the month we are in, if useMonth is True)

        // At this point we need to process the WEEK_OF_MONTH or
        // WEEK_OF_YEAR, which are similar, or the DAY_OF_WEEK_IN_MONTH.
        // First, perform initial shared computations.  These locate the
        // first week of the period.

        // Get the 0-based localized DOW of day one of the month or year.
        // Valid range 0..6.
        $first = $this->julianDayToDayOfWeek($julianDay + 1) - $firstDayOfWeek;
        if ($first < 0) {
            $first += 7;
        }

        $dowLocal = $this->getLocalDOW();

        // Find the first target DOW (dowLocal) in the month or year.
        // Actually, it may be just before the first of the month or year.
        // It will be an integer from -5..7.
        $date = 1 - $first + $dowLocal;

        if ($bestField == DateDefinitions::DAY_OF_WEEK_IN_MONTH) {
            // Adjust the target DOW to be in the month or year.
            if ($date < 1) {
                $date += 7;
            }

            // The only trickiness occurs if the day-of-week-in-month is
            // negative.
            $dim = $this->internalGet(DateDefinitions::DAY_OF_WEEK_IN_MONTH, 1);
            if ($dim >= 0) {
                $date += 7 * ($dim - 1);
            } else {
                // Move date to the last of this day-of-week in this month,
                // then back up as needed.  If dim==-1, we don't back up at
                // all.  If dim==-2, we back up once, etc.  Don't back up
                // past the first of the given day-of-week in this month.
                // Note that we handle -2, -3, etc. correctly, even though
                // values < -1 are technically disallowed.
                $m = $this->internalGet(DateDefinitions::MONTH, DateDefinitions::JANUARY);
                $monthLength = $this->handleGetMonthLength($year, $m);
                $date += ((int)(($monthLength - $date) / 7) + $dim + 1) * 7;
            }
        } else {
            if ($bestField == DateDefinitions::WEEK_OF_YEAR) {  // ------------------------------------- WOY -------------
                if (!$this->_isSet(DateDefinitions::YEAR_WOY) ||  // YWOY not set at all or
                    (
                        ($this->resolveFields(self::$kYearPrecedence) != DateDefinitions::YEAR_WOY) // YWOY doesn't have precedence
                        && ($this->fStamp[DateDefinitions::YEAR_WOY] != self::kInternallySet) // (excluding where all fields are internally set - then YWOY is used)
                    )
                ) {
                    // need to be sure to stay in 'real' year.
                    $woy = $this->internalGet($bestField);

                    $nextJulianDay = $this->handleComputeMonthStart($year + 1, 0, false); // jd of day before jan 1
                    $nextFirst = $this->julianDayToDayOfWeek($nextJulianDay + 1) - $firstDayOfWeek;

                    if ($nextFirst < 0) { // 0..6 ldow of Jan 1
                        $nextFirst += 7;
                    }

                    if ($woy == 1) {  // FIRST WEEK ---------------------------------

                        // nextFirst is now the localized DOW of Jan 1  of y-woy+1
                        if (($nextFirst > 0) &&   // Jan 1 starts on FDOW

This code seems to be duplicated across your project.

                            (7 - $nextFirst) >= $this->getMinimalDaysInFirstWeek() // or enough days in the week
                        ) {
                            // Jan 1 of (yearWoy+1) is in yearWoy+1 - recalculate JD to next year
                            $julianDay = $nextJulianDay;

                            // recalculate 'first' [0-based local dow of jan 1]
                            $first = $this->julianDayToDayOfWeek($julianDay + 1) - $firstDayOfWeek;
                            if ($first < 0) {
                                $first += 7;
                            }
                            // recalculate date.
                            $date = 1 - $first + $dowLocal;
                        }
                    } elseif ($woy >= $this->getLeastMaximum($bestField)) {
                        // could be in the last week- find out if this JD would overstep
                        $testDate = $date;
                        if ((7 - $first) < $this->getMinimalDaysInFirstWeek()) {
                            $testDate += 7;
                        }

                        // Now adjust for the week number.
                        $testDate += 7 * ($woy - 1);

                        if ($julianDay + $testDate > $nextJulianDay) { // is it past Dec 31?  (nextJulianDay is day BEFORE year+1's  Jan 1)

This code seems to be duplicated across your project.

                            // Fire up the calculating engines.. retry YWOY = (year-1)
                            $julianDay = $this->handleComputeMonthStart($year - 1, 0, false); // jd before Jan 1 of previous year
                            $first = $this->julianDayToDayOfWeek($julianDay + 1) - $firstDayOfWeek; // 0 based local dow   of first week

                            if ($first < 0) { // 0..6
                                $first += 7;
                            }
                            $date = 1 - $first + $dowLocal;
                        } /* correction needed */
                    } /* leastmaximum */
                } /* resolvefields(year) != year_woy */
            } /* bestfield != week_of_year */

            // assert(bestField == WEEK_OF_MONTH || bestField == WEEK_OF_YEAR)
            // Adjust for minimal days in first week
            if ((7 - $first) < $this->getMinimalDaysInFirstWeek()) {
                $date += 7;
            }

            // Now adjust for the week number.
            $date += 7 * ($this->internalGet($bestField) - 1);
        }

        return $julianDay + $date;
    }

    /**
     * Subclasses must override this to convert from week fields
     * (YEAR_WOY and WEEK_OF_YEAR) to an extended year in the case
     * where YEAR, EXTENDED_YEAR are not set.
     * The Calendar implementation assumes yearWoy is in extended gregorian form
     *
     * @internal
     *
     * @param      int $yearWoy
     * @param      int $woy
     *
     * @return     int the extended year, UCAL_EXTENDED_YEAR
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function handleGetExtendedYearFromWeekFields($yearWoy, $woy)
    {
        // We have UCAL_YEAR_WOY and UCAL_WEEK_OF_YEAR - from those, determine
        // what year we fall in, so that other code can set it properly.
        // (code borrowed from computeWeekFields and handleComputeJulianDay)
        //return yearWoy;

        // First, we need a reliable DOW.
        $bestField = $this->resolveFields(self::$kDatePrecedence); // !! Note: if subclasses have a different table, they should override handleGetExtendedYearFromWeekFields

        // Now, a local DOW
        $dowLocal = $this->getLocalDOW(); // 0..6
        $firstDayOfWeek = $this->getFirstDayOfWeek(); // Localized fdw
        $jan1Start = $this->handleComputeMonthStart($yearWoy, 0, false);
        $nextJan1Start = $this->handleComputeMonthStart($yearWoy + 1, 0, false); // next year's Jan1 start

        // At this point julianDay is the 0-based day BEFORE the first day of
        // January 1, year 1 of the given calendar.  If julianDay == 0, it
        // specifies (Jan. 1, 1) - 1, in whatever calendar we are using (Julian
        // or Gregorian). (or it is before the month we are in, if useMonth is True)

        // At this point we need to process the WEEK_OF_MONTH or
        // WEEK_OF_YEAR, which are similar, or the DAY_OF_WEEK_IN_MONTH.
        // First, perform initial shared computations.  These locate the
        // first week of the period.

        // Get the 0-based localized DOW of day one of the month or year.
        // Valid range 0..6.
        $first = $this->julianDayToDayOfWeek($jan1Start + 1) - $firstDayOfWeek;
        if ($first < 0) {
            $first += 7;
        }
        $nextFirst = $this->julianDayToDayOfWeek($nextJan1Start + 1) - $firstDayOfWeek;
        if ($nextFirst < 0) {
            $nextFirst += 7;
        }

        $minDays = $this->getMinimalDaysInFirstWeek();
        $jan1InPrevYear = false;  // January 1st in the year of WOY is the 1st week?  (i.e. first week is < minimal )
        //UBool nextJan1InPrevYear = false; // January 1st of Year of WOY + 1 is in the first week?

        if ((7 - $first) < $minDays) {
            $jan1InPrevYear = true;
        }

        //   if((7 - nextFirst) < minDays) {

42% of this comment could be valid code. Did you maybe forget this after debugging?

        //     nextJan1InPrevYear = true;
        //   }

        switch ($bestField) {
            case DateDefinitions::WEEK_OF_YEAR:
                if ($woy == 1) {
                    if ($jan1InPrevYear == true) {

It seems like you are loosely comparing two booleans. Considering using the strict comparison === instead.

                        // the first week of January is in the previous year
                        // therefore WOY1 is always solidly within yearWoy
                        return $yearWoy;
                    } else {
                        // First WOY is split between two years
                        if ($dowLocal < $first) { // we are prior to Jan 1
                            return $yearWoy - 1; // previous year
                        } else {
                            return $yearWoy; // in this year
                        }
                    }
                } elseif ($woy >= $this->getLeastMaximum($bestField)) {
                    // we _might_ be in the last week..
                    $jd =  // Calculate JD of our target day:
                                $jan1Start +  // JD of Jan 1
                                (7 - $first) + //  days in the first week (Jan 1.. )
                                ($woy - 1) * 7 + // add the weeks of the year
                                $dowLocal;   // the local dow (0..6) of last week
                    if ($jan1InPrevYear == false) {

It seems like you are loosely comparing two booleans. Considering using the strict comparison === instead.

                        $jd -= 7; // woy already includes Jan 1's week.
                    }

                    if (($jd + 1) >= $nextJan1Start) {
                        // we are in week 52 or 53 etc. - actual year is yearWoy+1
                        return $yearWoy + 1;
                    } else {
                        // still in yearWoy;
                        return $yearWoy;
                    }
                } else {
                    // we're not possibly in the last week -must be ywoy
                    return $yearWoy;
                }
                break;

break; does not seem to be reachable.

            case DateDefinitions::DATE:
                if (($this->internalGet(DateDefinitions::MONTH)==0) &&
                        ($woy >= $this->getLeastMaximum(DateDefinitions::WEEK_OF_YEAR))) {
                    return $yearWoy + 1; // month 0, late woy = in the next year
                } elseif ($woy == 1) {
                    //if(nextJan1InPrevYear) {

67% of this comment could be valid code. Did you maybe forget this after debugging?

                    if ($this->internalGet(DateDefinitions::MONTH)==0) {
                        return $yearWoy;
                    } else {
                        return $yearWoy - 1;
                    }
                    //}
                }

                //(internalGet(UCAL_DATE) <= (7-first)) /* && in minDow  */ ) {
                //within 1st week and in this month..
                //return yearWoy+1;

50% of this comment could be valid code. Did you maybe forget this after debugging?

                return $yearWoy;
                break;

break is not strictly necessary here and could be removed.

            default: // assume the year is appropriate
                return $yearWoy;
                break;

break is not strictly necessary here and could be removed.

        }
    }

    /**
     * Compute the Julian day from fields.  Will determine whether to use
     * the JULIAN_DAY field directly, or other fields.
     *
     * @return     int the julian day
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function computeJulianDay()
    {
        // We want to see if any of the date fields is newer than the
        // JULIAN_DAY.  If not, then we use JULIAN_DAY.  If so, then we do
        // the normal resolution.  We only use JULIAN_DAY if it has been
        // set by the user.  This makes it possible for the caller to set
        // the calendar to a time and call clear(MONTH) to reset the MONTH
        // to January.  This is legacy behavior.  Without this,
        // clear(MONTH) has no effect, since the internally set JULIAN_DAY
        // is used.
        if ($this->fStamp[DateDefinitions::JULIAN_DAY] >= (int)self::kMinimumUserStamp) {
            $bestStamp = $this->newestStamp(DateDefinitions::ERA, DateDefinitions::DAY_OF_WEEK_IN_MONTH, self::kUnset);
            $bestStamp = $this->newestStamp(DateDefinitions::YEAR_WOY, DateDefinitions::EXTENDED_YEAR, $bestStamp);
            if ($bestStamp <= $this->fStamp[DateDefinitions::JULIAN_DAY]) {
                return $this->internalGet(DateDefinitions::JULIAN_DAY);
            }
        }

        $bestField = $this->resolveFields($this->getFieldResolutionTable());
        if ($bestField == DateDefinitions::FIELD_COUNT) {
            $bestField = DateDefinitions::DAY_OF_MONTH;
        }

        return $this->handleComputeJulianDay($bestField);
    }

    /**
     * Compute the milliseconds in the day from the fields.  This is a
     * value from 0 to 23:59:59.999 inclusive, unless fields are out of
     * range, in which case it can be an arbitrary value.  This value
     * reflects local zone wall time.
     *
     * @return     int The milliseconds in the day
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function computeMillisInDay()
    {
        // Do the time portion of the conversion.

        $millisInDay = 0;

        // Find the best set of fields specifying the time of day.  There
        // are only two possibilities here; the HOUR_OF_DAY or the
        // AM_PM and the HOUR.
        $hourOfDayStamp = $this->fStamp[DateDefinitions::HOUR_OF_DAY];
        $hourStamp = ($this->fStamp[DateDefinitions::HOUR] > $this->fStamp[DateDefinitions::AM_PM]) ? $this->fStamp[DateDefinitions::HOUR] : $this->fStamp[DateDefinitions::AM_PM];
        $bestStamp = ($hourStamp > $hourOfDayStamp) ? $hourStamp : $hourOfDayStamp;

        // Hours
        if ($bestStamp != self::kUnset) {
            if ($bestStamp == $hourOfDayStamp) {
                // Don't normalize here; let overflow bump into the next period.
                // This is consistent with how we handle other fields.
                $millisInDay += $this->internalGet(DateDefinitions::HOUR_OF_DAY);
            } else {
                // Don't normalize here; let overflow bump into the next period.
                // This is consistent with how we handle other fields.
                $millisInDay += $this->internalGet(DateDefinitions::HOUR);
                $millisInDay += 12 * $this->internalGet(DateDefinitions::AM_PM); // Default works for unset AM_PM
            }
        }

        // We use the fact that unset == 0; we start with millisInDay
        // == HOUR_OF_DAY.
        $millisInDay *= 60;
        $millisInDay += $this->internalGet(DateDefinitions::MINUTE); // now have minutes
        $millisInDay *= 60;
        $millisInDay += $this->internalGet(DateDefinitions::SECOND); // now have seconds
        $millisInDay *= 1000;
        $millisInDay += $this->internalGet(DateDefinitions::MILLISECOND); // now have millis

        return $millisInDay;
    }

    /**
     * This method can assume EXTENDED_YEAR has been set.
     *
     * @param      double $millis milliseconds of the date fields
     * @param      int    $millisInDay milliseconds of the time fields; may be out or range.
     *
     * @return     int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function computeZoneOffset($millis, $millisInDay)
    {
        $rawOffset = $dstOffset = 0;
        $this->getTimeZone()->getOffsetRef($millis + $millisInDay, true, $rawOffset, $dstOffset);
        return $rawOffset + $dstOffset;
        // Note: Because we pass in wall millisInDay, rather than
        // standard millisInDay, we interpret "1:00 am" on the day
        // of cessation of DST as "1:00 am Std" (assuming the time
        // of cessation is 2:00 am).
    }

    /**
     * Determine the best stamp in a range.
     *
     * @param      int    $first first enum to look at
     * @param      int    $last last enum to look at
     * @param      int    $bestStampSoFar stamp prior to function call
     *
     * @return     int    the stamp value of the best stamp
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function newestStamp($first, $last, $bestStampSoFar)
    {
        $bestStamp = $bestStampSoFar;
        for ($i = (int) $first; $i <= (int) $last; ++$i) {
            if ($this->fStamp[$i] > $bestStamp) {
                $bestStamp = $this->fStamp[$i];
            }
        }
        return $bestStamp;
    }

    /**
     * @var        array Precedence table for Dates
     * @see #resolveFields
     * @internal
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    static $kDatePrecedence = array(

The visibility should be declared for property $kDatePrecedence.

        array(
            array(DateDefinitions::DAY_OF_MONTH, self::RESOLVE_STOP),
            array(DateDefinitions::WEEK_OF_YEAR, DateDefinitions::DAY_OF_WEEK, self::RESOLVE_STOP),
            array(DateDefinitions::WEEK_OF_MONTH, DateDefinitions::DAY_OF_WEEK, self::RESOLVE_STOP),
            array(DateDefinitions::DAY_OF_WEEK_IN_MONTH, DateDefinitions::DAY_OF_WEEK, self::RESOLVE_STOP),
            array(DateDefinitions::WEEK_OF_YEAR, DateDefinitions::DOW_LOCAL, self::RESOLVE_STOP),
            array(DateDefinitions::WEEK_OF_MONTH, DateDefinitions::DOW_LOCAL, self::RESOLVE_STOP),
            array(DateDefinitions::DAY_OF_WEEK_IN_MONTH, DateDefinitions::DOW_LOCAL, self::RESOLVE_STOP),
            array(DateDefinitions::DAY_OF_YEAR, self::RESOLVE_STOP),
            //    kResolveRemap | UCAL_DAY_OF_MONTH
            array(37, DateDefinitions::YEAR, self::RESOLVE_STOP),  // if YEAR is set over YEAR_WOY use DAY_OF_MONTH
            //    kResolveRemap | UCAL_WEEK_OF_YEAR
            array(35, DateDefinitions::YEAR_WOY, self::RESOLVE_STOP),  // if YEAR_WOY is set,  calc based on WEEK_OF_YEAR
            array(self::RESOLVE_STOP),
        ),
        array(
            array(DateDefinitions::WEEK_OF_YEAR, self::RESOLVE_STOP),
            array(DateDefinitions::WEEK_OF_MONTH, self::RESOLVE_STOP),
            array(DateDefinitions::DAY_OF_WEEK_IN_MONTH, self::RESOLVE_STOP),
            //    kResolveRemap | UCAL_DAY_OF_WEEK_IN_MONTH
            array(40, DateDefinitions::DAY_OF_WEEK, self::RESOLVE_STOP),
            //    self::kResolveRemap | UCAL_DAY_OF_WEEK_IN_MONTH

38% of this comment could be valid code. Did you maybe forget this after debugging?

            array(40, DateDefinitions::DOW_LOCAL, self::RESOLVE_STOP),
            array(self::RESOLVE_STOP),
        ),
        array(
            array(self::RESOLVE_STOP),
        ),
    );

    /**
     * @var        array Precedence table for Year
     * @see #resolveFields
     * @internal
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected static $kYearPrecedence = array(
        array(
            array(DateDefinitions::YEAR, self::RESOLVE_STOP),
            array(DateDefinitions::EXTENDED_YEAR, self::RESOLVE_STOP),
            array(DateDefinitions::YEAR_WOY, DateDefinitions::WEEK_OF_YEAR, self::RESOLVE_STOP),  // YEAR_WOY is useless without WEEK_OF_YEAR
            array(self::RESOLVE_STOP),
        ),
        array(
            array(self::RESOLVE_STOP),
        ),
    );

    /**
     * @var        array Precedence table for Day of Week
     * @see #resolveFields
     * @internal
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected static $kDOWPrecedence = array(
        array(
            array(DateDefinitions::DAY_OF_WEEK, self::RESOLVE_STOP, self::RESOLVE_STOP),
            array(DateDefinitions::DOW_LOCAL, self::RESOLVE_STOP, self::RESOLVE_STOP),
            array(self::RESOLVE_STOP),
        ),
        array(
            array(self::RESOLVE_STOP),
        ),
    );

    /**
     * Given a precedence table, return the newest field combination in
     * the table, or UCAL_FIELD_COUNT if none is found.
     *
     * <p>The precedence table is a 3-dimensional array of integers.  It
     * may be thought of as an array of groups.  Each group is an array of
     * lines.  Each line is an array of field numbers.  Within a line, if
     * all fields are set, then the time stamp of the line is taken to be
     * the stamp of the most recently set field.  If any field of a line is
     * unset, then the line fails to match.  Within a group, the line with
     * the newest time stamp is selected.  The first field of the line is
     * returned to indicate which line matched.
     *
     * <p>In some cases, it may be desirable to map a line to field that
     * whose stamp is NOT examined.  For example, if the best field is
     * DAY_OF_WEEK then the DAY_OF_WEEK_IN_MONTH algorithm may be used.  In
     * order to do this, insert the value <code>kResolveRemap | F</code> at
     * the start of the line, where <code>F</code> is the desired return
     * field value.  This field will NOT be examined; it only determines
     * the return value if the other fields in the line are the newest.
     *
     * <p>If all lines of a group contain at least one unset field, then no
     * line will match, and the group as a whole will fail to match.  In
     * that case, the next group will be processed.  If all groups fail to
     * match, then UCAL_FIELD_COUNT is returned.
     * @internal
     *
     * @param      array $precedenceTable the precedence table
     *
     * @return     int   the best field
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function resolveFields($precedenceTable)
    {
        $bestField = DateDefinitions::FIELD_COUNT;
        for ($g = 0; $precedenceTable[$g][0][0] != -1 && ($bestField == DateDefinitions::FIELD_COUNT); ++$g) {
            $bestStamp = self::kUnset;
            for ($l = 0; $precedenceTable[$g][$l][0] != -1; ++$l) {
                $lineStamp = self::kUnset;
                // Skip over first entry if it is negative
                for ($i = (($precedenceTable[$g][$l][0] >= self::RESOLVE_REMAP) ? 1 : 0); $precedenceTable[$g][$l][$i] != -1; ++$i) {
                    $s = $this->fStamp[$precedenceTable[$g][$l][$i]];

                    // If any field is unset then don't use this line
                    if ($s == self::kUnset) {
//					goto linesInGroup;
                        continue 2;
                    } elseif ($s > $lineStamp) {
                        $lineStamp = $s;
                    }
                }
                // Record new maximum stamp & field no.
                if ($lineStamp > $bestStamp) {
                    $bestStamp = $lineStamp;
                    $bestField = $precedenceTable[$g][$l][0]; // First field refers to entire line
                }
//linesInGroup:
            }
        }
        return ($bestField >= self::RESOLVE_REMAP) ? ($bestField & (self::RESOLVE_REMAP - 1)) : $bestField ;
    }

    /**
     * @return     array
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getFieldResolutionTable()
    {
        return self::$kDatePrecedence;
    }

    /**
     * Return the field that is newer, either defaultField, or alternateField.
     * If neither is newer or neither is set, return defaultField.
     * @internal
     *
     * @param      int
     * @param      int
     *
     * @return     int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function newerField($defaultField, $alternateField)
    {
        if ($this->fStamp[$alternateField] > $this->fStamp[$defaultField]) {
            return $alternateField;
        }
        return $defaultField;
    }

    /**
     * Helper function for calculating limits by trial and error
     *
     * @param      int    $field The field being investigated
     * @param      int    $startValue starting (least max) value of field
     * @param      int    $endValue ending (greatest max) value of field
     *
     * @return     int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getActualHelper($field, $startValue, $endValue)
    {
        if ($startValue == $endValue) {
            // if we know that the maximum value is always the same, just return it
            return $startValue;
        }

        $delta = ($endValue > $startValue) ? 1 : -1;

        // clone the calendar so we don't mess with the real one, and set it to
        // accept anything for the field values
        $work = clone $this;
        $work->setLenient(true);
        $work->prepareGetActual($field, $delta < 0);

        // now try each value from the start to the end one by one until
        // we get a value that normalizes to another value.  The last value that
        // normalizes to itself is the actual maximum for the current date
        $result = $startValue;
        do {

This code seems to be duplicated across your project.

            $work->set($field, $startValue);
            if ($work->get($field) != $startValue) {
                break;
            } else {
                $result = $startValue;
                $startValue += $delta;
            }
        } while ($result != $endValue);

        return $result;
    }

    /**
     * @var        bool The flag which indicates if the current time is set in the
     *                  calendar.
     */
    protected $fIsTimeSet = false;

    /**
     * @var        bool True if the fields are in sync with the currently set time
     *                  of this Calendar. If false, then the next attempt to get
     *                  the value of a field will force a recomputation of all
     *                  fields from the current value of the time field.
     */
    protected $fAreFieldsInSync = false;

    /**
     * @var        bool True if all of the fields have been set.  This is
     *                  initially false, and set to true by computeFields().
     */
    protected $fAreAllFieldsSet = false;

    /**
     * @var        bool True if all fields have been virtually set, but have not
     *                  yet been computed.  This occurs only in setTimeInMillis().
     *                  A calendar set to this state will compute all fields from
     *                  the time if it becomes necessary, but otherwise will delay
     *                  such computation.
     */
    protected $fAreFieldsVirtuallySet = false;

    /**
     * Get the current time without recomputing.
     *
     * @return     float the current time without recomputing.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function internalGetTime()
    {
        return $this->fTime;
    }

    /**
     * Set the current time without affecting flags or fields.
     *
     * @param      float $time The time to be set
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function internalSetTime($time)
    {
        $this->fTime = $time;
    }

    /**
     * @var        array The time fields containing values into which the millis
     *                   is computed.
     */
    protected $fFields;

    /**
     * @var        array The flags which tell if a specified time field for the
     *                   calendar is set.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     *
     * @deprecated ICU 2.8 use (fStamp[n]!=kUnset)
     */
    protected $fIsSet;

    /** Special values of stamp[]
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    const kUnset                 = 0;
    const kInternallySet         = 1;
    const kMinimumUserStamp      = 2;

    /**
     * @var        array Pseudo-time-stamps which specify when each field was set.
     *                   There are two special values, UNSET and INTERNALLY_SET.
     *                   Values from MINIMUM_USER_SET to Integer.MAX_VALUE are
     *                   legal user set values.
     */
    protected $fStamp;

    /**
     * Subclasses may override this method to compute several fields
     * specific to each calendar system.  These are:
     *
     * <ul><li>DateDefinitions::ERA
     * <li>DateDefinitions::YEAR
     * <li>DateDefinitions::MONTH
     * <li>DateDefinitions::DAY_OF_MONTH
     * <li>DateDefinitions::DAY_OF_YEAR
     * <li>DateDefinitions::EXTENDED_YEAR</ul>
     *
     * Subclasses can refer to the DAY_OF_WEEK and DOW_LOCAL fields, which
     * will be set when this method is called.  Subclasses can also call
     * the getGregorianXxx() methods to obtain Gregorian calendar
     * equivalents for the given Julian day.
     *
     * <p>In addition, subclasses should compute any subclass-specific
     * fields, that is, fields from BASE_FIELD_COUNT to
     * getFieldCount() - 1.
     *
     * <p>The default implementation in <code>Calendar</code> implements
     * a pure proleptic Gregorian calendar.
     * @internal
     *
     * @param      int $julianDay The julian day
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function handleComputeFields($julianDay)
    {
        $this->internalSet(DateDefinitions::MONTH, $this->getGregorianMonth());
        $this->internalSet(DateDefinitions::DAY_OF_MONTH, $this->getGregorianDayOfMonth());
        $this->internalSet(DateDefinitions::DAY_OF_YEAR, $this->getGregorianDayOfYear());
        $eyear = $this->getGregorianYear();
        $this->internalSet(DateDefinitions::EXTENDED_YEAR, $eyear);
        $era = GregorianCalendar::AD;
        if ($eyear < 1) {
            $era = GregorianCalendar::BC;
            $eyear = 1 - $eyear;
        }
        $this->internalSet(DateDefinitions::ERA, $era);
        $this->internalSet(DateDefinitions::YEAR, $eyear);
    }

    /**
     * Return the extended year on the Gregorian calendar as computed by
     * <code>computeGregorianFields()</code>.
     * @see        Calendar::computeGregorianFields
     * @internal
     *
     * @return     int The gregorian year
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getGregorianYear()
    {
        return $this->fGregorianYear;
    }

    /**
     * Return the month (0-based) on the Gregorian calendar as computed by
     * <code>computeGregorianFields()</code>.
     * @see        Calendar::computeGregorianFields
     * @internal
     *
     * @return     int The gregorian month
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getGregorianMonth()
    {
        return $this->fGregorianMonth;
    }

    /**
     * Return the day of year (1-based) on the Gregorian calendar as
     * computed by <code>computeGregorianFields()</code>.
     * @see        Calendar::computeGregorianFields
     * @internal
     *
     * @return     int The gregorian day of year
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getGregorianDayOfYear()
    {
        return $this->fGregorianDayOfYear;
    }

    /**
     * Return the day of month (1-based) on the Gregorian calendar as
     * computed by <code>computeGregorianFields()</code>.
     * @see        Calendar::computeGregorianFields
     * @internal
     *
     * @return     int The gregorian day of month
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getGregorianDayOfMonth()
    {
        return $this->fGregorianDayOfMonth;
    }

    /**
     * Called by computeJulianDay.  Returns the default month (0-based) for the
     * year, taking year and era into account.  Defaults to 0 for Gregorian, which
     * doesn't care.
     *
     * @return     int The default month for the year.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getDefaultMonthInYear()
    {
        return 0;
    }

    /**
     * Called by computeJulianDay.  Returns the default day (1-based) for the
     * month, taking currently-set year and era into account.  Defaults to 1 for
     * Gregorian.
     *
     * @param      int $month The months
     *
     * @return     int The default day for the month
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getDefaultDayInMonth($month)

The parameter $month is not used and could be removed.

    {
        return 1;
    }

    //-------------------------------------------------------------------------
    // Protected utility methods for use by subclasses.  These are very handy
    // for implementing add, roll, and computeFields.
    //-------------------------------------------------------------------------

    /**
     * Adjust the specified field so that it is within
     * the allowable range for the date to which this calendar is set.
     * For example, in a Gregorian calendar pinning the
     * DateDefinitions::DAY_OF_MONTH field for a calendar set to April 31
     * would cause it to be set to April 30.
     * <p>
     * <b>Subclassing:</b>
     * <br>
     * This utility method is intended for use by subclasses that need to
     * implement their own overrides of {@link #roll roll} and {@link #add add}.
     * <p>
     * <b>Note:</b>
     * <code>pinField</code> is implemented in terms of
     * {@link #getActualMinimum getActualMinimum}
     * and {@link #getActualMaximum getActualMaximum}.  If either of those methods
     * uses a slow, iterative algorithm for a particular field, it would be
     * unwise to attempt to call <code>pinField</code> for that field.  If you
     * really do need to do so, you should override this method to do
     * something more efficient for that field.
     * <p>
     *
     * @param      string $field The calendar field whose value should be pinned.
     *
     * @see        getActualMinimum
     * @see        getActualMaximum
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function pinField($field)
    {
        $max = $this->getActualMaximum($field);
        $min = $this->getActualMinimum($field);

        if ($this->fFields[$field] > $max) {
            $this->set($field, $max);
        } elseif ($this->fFields[$field] < $min) {
            $this->set($field, $min);
        }
    }

    /**
     * Return the week number of a day, within a period. This may be the week
     * number in a year or the week number in a month. Usually this will be a
     * value >= 1, but if some initial days of the period are excluded from
     * week 1, because getMinimalDaysInFirstWeek is > 1, then the week number will
     * be zero for those initial days. This method requires the day number and day
     * of week for some known date in the period in order to determine the day of
     * week on the desired day.
     * <p>
     * <b>Subclassing:</b>
     * <br>
     * This method is intended for use by subclasses in implementing their
     * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
     * It is often useful in {@link #getActualMinimum getActualMinimum} and
     * {@link #getActualMaximum getActualMaximum} as well.
     * <p>
     * This variant is handy for computing the week number of some other
     * day of a period (often the first or last day of the period) when its day
     * of the week is not known but the day number and day of week for some other
     * day in the period (e.g. the current date) <em>is</em> known.
     * <p>
     *
     * @param      int $desiredDay The {@link #UCalendarDateFields DAY_OF_YEAR} or
     *                 {@link #UCalendarDateFields DAY_OF_MONTH} whose week
     *                 number is desired.
     *                 Should be 1 for the first day of the period.
     *
     * @param      int $dayOfPeriod The {@link #UCalendarDateFields DAY_OF_YEAR}
     *                 or {@link #UCalendarDateFields DAY_OF_MONTH} for a day in
     *                 the period whose {@link #UCalendarDateFields DAY_OF_WEEK}
     *                 is specified by the <code>knownDayOfWeek</code> parameter.
     *                 Should be 1 for first day of period.
     *
     * @param      int $dayOfWeek The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
     *                 corresponding to the <code>knownDayOfPeriod</code>
     *                 parameter.
     *                 1-based with 1=Sunday.
     *
     * @return     int The week number (one-based), or zero if the day falls
     *                 before the first week because
     *                 {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
     *                 is more than one.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function weekNumber1($desiredDay, $dayOfPeriod, $dayOfWeek)
    {
        // Determine the day of the week of the first day of the period
        // in question (either a year or a month).  Zero represents the
        // first day of the week on this calendar.
        $periodStartDayOfWeek = ($dayOfWeek - $this->getFirstDayOfWeek() - $dayOfPeriod + 1) % 7;
        if ($periodStartDayOfWeek < 0) {
            $periodStartDayOfWeek += 7;
        }

        // Compute the week number.  Initially, ignore the first week, which
        // may be fractional (or may not be).  We add periodStartDayOfWeek in
        // order to fill out the first week, if it is fractional.
        $weekNo = (int) (($desiredDay + $periodStartDayOfWeek - 1) / 7);

        // If the first week is long enough, then count it.  If
        // the minimal days in the first week is one, or if the period start
        // is zero, we always increment weekNo.
        if ((7 - $periodStartDayOfWeek) >= $this->getMinimalDaysInFirstWeek()) {
            ++$weekNo;
        }

        return $weekNo;
    }

    /**
     * Return the week number of a day, within a period. This may be the week number in
     * a year, or the week number in a month. Usually this will be a value >= 1, but if
     * some initial days of the period are excluded from week 1, because
     * {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek} is > 1,
     * then the week number will be zero for those
     * initial days. This method requires the day of week for the given date in order to
     * determine the result.
     * <p>
     * <b>Subclassing:</b>
     * <br>
     * This method is intended for use by subclasses in implementing their
     * {@link #computeTime computeTime} and/or {@link #computeFields computeFields} methods.
     * It is often useful in {@link #getActualMinimum getActualMinimum} and
     * {@link #getActualMaximum getActualMaximum} as well.
     * <p>
     * @param      int $dayOfPeriod The {@link #UCalendarDateFields DAY_OF_YEAR} or
     *                 {@link #UCalendarDateFields DAY_OF_MONTH} whose week
     *                 number is desired. Should be 1 for the first day of the
     *                 period.
     *
     * @param      int $dayOfWeek The {@link #UCalendarDateFields DAY_OF_WEEK} for the day
     *                 corresponding to the <code>dayOfPeriod</code> parameter.
     *                 1-based with 1=Sunday.
     *
     * @return     int The week number (one-based), or zero if the day falls
     *                 before the first week because
     *                 {@link #getMinimalDaysInFirstWeek getMinimalDaysInFirstWeek}
     *                 is more than one.
     * @internal
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function weekNumber($dayOfPeriod, $dayOfWeek)
    {
        return $this->weekNumber1($dayOfPeriod, $dayOfPeriod, $dayOfWeek);
    }

    /**
     * returns the local DOW, valid range 0..6
     * @internal
     *
     * @return     int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function getLocalDOW()
    {
        // Get zero-based localized DOW, valid range 0..6.  This is the DOW
        // we are looking for.
        $dowLocal = 0;
        switch ($this->resolveFields(self::$kDOWPrecedence)) {
            case DateDefinitions::DAY_OF_WEEK:
                $dowLocal = $this->internalGet(DateDefinitions::DAY_OF_WEEK) - $this->fFirstDayOfWeek;
                break;
            case DateDefinitions::DOW_LOCAL:
                $dowLocal = $this->internalGet(DateDefinitions::DOW_LOCAL) - 1;
                break;
            default:
                break;
        }
        $dowLocal = $dowLocal % 7;
        if ($dowLocal < 0) {
            $dowLocal += 7;
        }
        return $dowLocal;
    }

    /**
     * @var        int The next available value for fStamp[]
     */
    private $fNextStamp = 1;// = MINIMUM_USER_STAMP;

    /**
     * @var        float The current time set for the calendar.
     */
    private $fTime;

    /**
     * @see   #setLenient
     * @var        bool
     */
    private $fLenient;

    /**
     * @var        TimeZone Time zone affects the time calculation done by
     *                           Calendar. Calendar subclasses use the time zone
     *                           data to produce the local time.
     */
    private $fZone;

    /**
     * Both firstDayOfWeek and minimalDaysInFirstWeek are locale-dependent. They are
     * used to figure out the week count for a specific date for a given locale. These
     * must be set when a Calendar is constructed. For example, in US locale,
     * firstDayOfWeek is SUNDAY; minimalDaysInFirstWeek is 1. They are used to figure
     * out the week count for a specific date for a given locale. These must be set when
     * a Calendar is constructed.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private $fFirstDayOfWeek;
    private $fMinimalDaysInFirstWeek;

    /**
     * Sets firstDayOfWeek and minimalDaysInFirstWeek. Called at Calendar construction
     * time.
     *
     * @param      Locale $desiredLocale The given locale.
     * @param      string $type The calendar type identifier, e.g: gregorian,
     *                    buddhist, etc.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function setWeekCountData(Locale $desiredLocale, $type)

The parameter $type is not used and could be removed.

    {
        // Read the week count data from the resource bundle.  This should
        // have the form:
        //
        //   DateTimeElements:intvector {
        //      1,    // first day of week
        //      1     // min days in week
        //   }
        //   Both have a range of 1..7

        $this->fFirstDayOfWeek = DateDefinitions::SUNDAY;
        $this->fMinimalDaysInFirstWeek = 1;

        $tm = $desiredLocale->getContext()->getTranslationManager();
        $cdata = $tm->getTerritoryData($desiredLocale->getLocaleTerritory());
        if (isset($cdata['week']['firstDay'])) {
            $this->fFirstDayOfWeek = (int) $cdata['week']['firstDay'];
        }
        if (isset($cdata['week']['minDays'])) {
            $this->fMinimalDaysInFirstWeek = (int) $cdata['week']['minDays'];
        }
    }

    /**
     * Recompute the time and update the status fields isTimeSet
     * and areFieldsSet.  Callers should check isTimeSet and only
     * call this method if isTimeSet is false.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function updateTime()
    {
        $this->computeTime();

        // If we are lenient, we need to recompute the fields to normalize
        // the values.  Also, if we haven't set all the fields yet (i.e.,
        // in a newly-created object), we need to fill in the fields. [LIU]
        if ($this->isLenient() || ! $this->fAreAllFieldsSet) {
            $this->fAreFieldsInSync = false;
        }

        $this->fIsTimeSet = true;
        $this->fAreFieldsVirtuallySet = false;
    }

    /**
     * @var        int The Gregorian year, as computed by computeGregorianFields()
     *                 and returned by getGregorianYear().
     * @see        Calendar::computeGregorianFields
     */
    private $fGregorianYear;

    /**
     * @var        int The Gregorian month, as computed by
     *                 computeGregorianFields() and returned by
     *                 getGregorianMonth().
     * @see        Calendar::computeGregorianFields
     */
    private $fGregorianMonth;

    /**
     * @var        int The Gregorian day of the year, as computed by
     *                 computeGregorianFields() and returned by
     *                 getGregorianDayOfYear().
     * @see        Calendar::computeGregorianFields
     */
    private $fGregorianDayOfYear;

    /**
     * @var        int The Gregorian day of the month, as computed by
     *                 computeGregorianFields() and returned by
     *                 getGregorianDayOfMonth().
     * @see        Calendar::computeGregorianFields
     */
    private $fGregorianDayOfMonth;

    /* calculations */

    /**
     * Compute the Gregorian calendar year, month, and day of month from
     * the given Julian day.  These values are not stored in fields, but in
     * member variables gregorianXxx.  Also compute the DAY_OF_WEEK and
     * DOW_LOCAL fields.
     *
     * @param      int $julianDay The julian day
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function computeGregorianAndDOWFields($julianDay)
    {
        $this->computeGregorianFields($julianDay);

        // Compute day of week: JD 0 = Monday
        $dow = $this->julianDayToDayOfWeek($julianDay);
        $this->internalSet(DateDefinitions::DAY_OF_WEEK, $dow);

        // Calculate 1-based localized day of week
        $dowLocal = $dow - $this->getFirstDayOfWeek() + 1;
        if ($dowLocal < 1) {
            $dowLocal += 7;
        }
        $this->internalSet(DateDefinitions::DOW_LOCAL, $dowLocal);
        $this->fFields[DateDefinitions::DOW_LOCAL] = $dowLocal;
    }

    /**
     * Compute the Gregorian calendar year, month, and day of month from the
     * Julian day.  These values are not stored in fields, but in member
     * variables gregorianXxx.  They are used for time zone computations and by
     * subclasses that are Gregorian derivatives.  Subclasses may call this
     * method to perform a Gregorian calendar millis->fields computation.
     * To perform a Gregorian calendar fields->millis computation, call
     * computeGregorianMonthStart().
     * @see #computeGregorianMonthStart
     *
     * @param      int $julianDay The julian day
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function computeGregorianFields($julianDay)
    {
        $gregorianDayOfWeekUnused = 0;
        CalendarGrego::dayToFields($julianDay - DateDefinitions::EPOCH_START_AS_JULIAN_DAY, $this->fGregorianYear, $this->fGregorianMonth, $this->fGregorianDayOfMonth, $gregorianDayOfWeekUnused, $this->fGregorianDayOfYear);
    }

    /**
     * Compute the fields WEEK_OF_YEAR, YEAR_WOY, WEEK_OF_MONTH,
     * DAY_OF_WEEK_IN_MONTH, and DOW_LOCAL from EXTENDED_YEAR, YEAR,
     * DAY_OF_WEEK, and DAY_OF_YEAR.  The latter fields are computed by the
     * subclass based on the calendar system.
     *
     * <p>The YEAR_WOY field is computed simplistically.  It is equal to YEAR
     * most of the time, but at the year boundary it may be adjusted to YEAR-1
     * or YEAR+1 to reflect the overlap of a week into an adjacent year.  In
     * this case, a simple increment or decrement is performed on YEAR, even
     * though this may yield an invalid YEAR value.  For instance, if the YEAR
     * is part of a calendar system with an N-year cycle field CYCLE, then
     * incrementing the YEAR may involve incrementing CYCLE and setting YEAR
     * back to 0 or 1.  This is not handled by this code, and in fact cannot be
     * simply handled without having subclasses define an entire parallel set of
     * fields for fields larger than or equal to a year.  This additional
     * complexity is not warranted, since the intention of the YEAR_WOY field is
     * to support ISO 8601 notation, so it will typically be used with a
     * proleptic Gregorian calendar, which has no field larger than a year.
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function computeWeekFields()
    {
        $eyear = $this->fFields[DateDefinitions::EXTENDED_YEAR];
        $year = $this->fFields[DateDefinitions::YEAR];
        $dayOfWeek = $this->fFields[DateDefinitions::DAY_OF_WEEK];
        $dayOfYear = $this->fFields[DateDefinitions::DAY_OF_YEAR];

        // WEEK_OF_YEAR start
        // Compute the week of the year.  For the Gregorian calendar, valid week
        // numbers run from 1 to 52 or 53, depending on the year, the first day
        // of the week, and the minimal days in the first week.  For other
        // calendars, the valid range may be different -- it depends on the year
        // length.  Days at the start of the year may fall into the last week of
        // the previous year; days at the end of the year may fall into the
        // first week of the next year.  ASSUME that the year length is less than
        // 7000 days.
        $yearOfWeekOfYear = $year;
        $relDow = ($dayOfWeek + 7 - $this->getFirstDayOfWeek()) % 7; // 0..6
        $relDowJan1 = ($dayOfWeek - $dayOfYear + 7001 - $this->getFirstDayOfWeek()) % 7; // 0..6
        $woy = (int) (($dayOfYear - 1 + $relDowJan1) / 7); // 0..53
        if ((7 - $relDowJan1) >= $this->getMinimalDaysInFirstWeek()) {
            ++$woy;
        }

        // Adjust for weeks at the year end that overlap into the previous or
        // next calendar year.
        if ($woy == 0) {
            // We are the last week of the previous year.
            // Check to see if we are in the last week; if so, we need
            // to handle the case in which we are the first week of the
            // next year.

            $prevDoy = $dayOfYear + $this->handleGetYearLength($eyear - 1);
            $woy = $this->weekNumber($prevDoy, $dayOfWeek);
            $yearOfWeekOfYear--;
        } else {
            $lastDoy = $this->handleGetYearLength($eyear);
            // Fast check: For it to be week 1 of the next year, the DOY
            // must be on or after L-5, where L is yearLength(), then it
            // cannot possibly be week 1 of the next year:
            //          L-5                  L
            // doy: 359 360 361 362 363 364 365 001

45% of this comment could be valid code. Did you maybe forget this after debugging?

            // dow:      1   2   3   4   5   6   7

44% of this comment could be valid code. Did you maybe forget this after debugging?

            if ($dayOfYear >= ($lastDoy - 5)) {
                $lastRelDow = ($relDow + $lastDoy - $dayOfYear) % 7;
                if ($lastRelDow < 0) {
                    $lastRelDow += 7;
                }
                if (((6 - $lastRelDow) >= $this->getMinimalDaysInFirstWeek()) &&
                        (($dayOfYear + 7 - $relDow) > $lastDoy)) {
                    $woy = 1;
                    $yearOfWeekOfYear++;
                }
            }
        }
        $this->fFields[DateDefinitions::WEEK_OF_YEAR] = $woy;
        $this->fFields[DateDefinitions::YEAR_WOY] = $yearOfWeekOfYear;
        // WEEK_OF_YEAR end

        $dayOfMonth = $this->fFields[DateDefinitions::DAY_OF_MONTH];
        $this->fFields[DateDefinitions::WEEK_OF_MONTH] = $this->weekNumber($dayOfMonth, $dayOfWeek);
        $this->fFields[DateDefinitions::DAY_OF_WEEK_IN_MONTH] = (int)(($dayOfMonth-1) / 7) + 1;
    }

    /**
     * Ensure that each field is within its valid range by calling {@link
     * #validateField(int, int&)} on each field that has been set.  This method
     * should only be called if this calendar is not lenient.
     * @see #isLenient
     * @see #validateField(int, int&)
     * @internal
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function validateFields()
    {
        for ($field = 0; $field < DateDefinitions::FIELD_COUNT; ++$field) {
            if ($this->_isSet($field)) {
                $this->validateField($field);
            }
        }
    }

    /**
     * Validate a single field of this calendar.  Subclasses should
     * override this method to validate any calendar-specific fields.
     * Generic fields can be handled by
     * <code>Calendar.validateField()</code>.
     * @see #validateField(int, int, int, int&)
     * @internal
     *
     * @param      int $field The field
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function validateField($field)
    {
        switch ($field) {
            case DateDefinitions::DAY_OF_MONTH:
                $y = $this->handleGetExtendedYear();
                $this->validateField1($field, 1, $this->handleGetMonthLength($y, $this->internalGet(DateDefinitions::MONTH)));
                break;
            case DateDefinitions::DAY_OF_YEAR:
                $y = $this->handleGetExtendedYear();
                $this->validateField1($field, 1, $this->handleGetYearLength($y));
                break;
            case DateDefinitions::DAY_OF_WEEK_IN_MONTH:
                if ($this->internalGet($field) == 0) {
                    throw new \InvalidArgumentException('DAY_OF_WEEK_IN_MONTH cannot be zero');
                }
                $this->validateField1($field, $this->getMinimum($field), $this->getMaximum($field));
                break;
            default:
                $this->validateField1($field, $this->getMinimum($field), $this->getMaximum($field));
                break;
        }
    }

    /**
     * Validate a single field of this calendar given its minimum and
     * maximum allowed value.  If the field is out of range,
     * <code>InvalidArgumentException</code> will be thrown.  Subclasses may
     * use this method in their implementation of {@link
     * #validateField(int, int&)}.
     * @internal
     *
     * @throws     <b>InvalidArgumentException</b>
     *
     * @param      string
     * @param      int
     * @param      int
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    private function validateField1($field, $min, $max)
    {
        $value = $this->fFields[$field];
        if ($value < $min || $value > $max) {
            throw new \InvalidArgumentException('Illegal argument error. Field: ' . $field . '. Value ' . $value . ' is not within ' . $min . ' and ' . $max);
        }
    }

    /**
     * Convert a quasi Julian date to the day of the week. The Julian date used here is
     * not a true Julian date, since it is measured from midnight, not noon. Return
     * value is one-based.
     *
     * @param      double $julian The given Julian date number.
     *
     * @return     int    Day number from 1..7 (SUN..SAT).
     *
     * @internal
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    protected function julianDayToDayOfWeek($julian)
    {
        // If julian is negative, then julian%7 will be negative, so we adjust
        // accordingly.  We add 1 because Julian day 0 is Monday.

        $dayOfWeek = fmod($julian + 1, 7);

        $result = ($dayOfWeek + (($dayOfWeek < 0) ? (7 + DateDefinitions::SUNDAY) : DateDefinitions::SUNDAY));
        return $result;
    }

    /**
     * @var        string
     */
    private $validLocale;

The property $validLocale is not used and could be removed.

    /**
     * @var        string
     */
    private $actualLocale;

The property $actualLocale is not used and could be removed.

    /**
     * @internal
     * @return     bool if this calendar has a default century (i.e. 03 -> 2003)
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract public function haveDefaultCentury();

    /**
     * @internal
     * @return     float the start of the default century, as a UDate
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract public function defaultCenturyStart();

    /**
     * @internal
     * @return     int the beginning year of the default century, as a year
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @author     The ICU Project
     * @since      0.11.0
     */
    abstract public function defaultCenturyStartYear();

    /**
     * Returns the type of the implementing calendar.
     *
     * @return     string The type of this calendar (Gregorian, ...)
     *
     * @author     Dominik del Bondio <ddb@bitxtender.com>
     * @since      0.11.0
     */
    abstract public function getType();
}