fisharebest / webtrees

app/Date/CalendarDate.php

Indentation +903 added lines, -903 removed lines

@@ -32,80 +32,80 @@ 
  * midday.
  */
 class CalendarDate {
-	/** @var int[] Convert GEDCOM month names to month numbers  */
-	public static $MONTH_ABBREV = array('' => 0, 'JAN' => 1, 'FEB' => 2, 'MAR' => 3, 'APR' => 4, 'MAY' => 5, 'JUN' => 6, 'JUL' => 7, 'AUG' => 8, 'SEP' => 9, 'OCT' => 10, 'NOV' => 11, 'DEC' => 12);
-
-	/** @var string[] Convert numbers to/from roman numerals */
-	protected static $roman_numerals = array(1000 => 'M', 900 => 'CM', 500 => 'D', 400 => 'CD', 100 => 'C', 90 => 'XC', 50 => 'L', 40 => 'XL', 10 => 'X', 9 => 'IX', 5 => 'V', 4 => 'IV', 1 => 'I');
-
-	/** @var CalendarInterface The calendar system used to represent this date */
-	protected $calendar;
-
-	/** @var int Year number  */
-	public $y;
-
-	/** @var int Month number  */
-	public $m;
-
-	/** @var int Day number  */
-	public $d;
-
-	/** @var int Earliest Julian day number (start of month/year for imprecise dates) */
-	public $minJD;
-
-	/** @var int Latest Julian day number (end of month/year for imprecise dates) */
-	public $maxJD;
-
-	/**
-	 * Create a date from either:
-	 * a Julian day number
-	 * day/month/year strings from a GEDCOM date
-	 * another CalendarDate object
-	 *
-	 * @param array|int|CalendarDate $date
-	 */
-	public function __construct($date) {
-		// Construct from an integer (a julian day number)
-		if (is_integer($date)) {
-			$this->minJD                       = $date;
-			$this->maxJD                       = $date;
-			list($this->y, $this->m, $this->d) = $this->calendar->jdToYmd($date);
-
-			return;
-		}
-
-		// Construct from an array (of three gedcom-style strings: "1900", "FEB", "4")
-		if (is_array($date)) {
-			$this->d = (int) $date[2];
-			if (array_key_exists($date[1], static::$MONTH_ABBREV)) {
-				$this->m = static::$MONTH_ABBREV[$date[1]];
-			} else {
-				$this->m = 0;
-				$this->d = 0;
-			}
-			$this->y = $this->extractYear($date[0]);
-
-			// Our simple lookup table above does not take into account Adar and leap-years.
-			if ($this->m === 6 && $this->calendar instanceof JewishCalendar && !$this->calendar->isLeapYear($this->y)) {
-				$this->m = 7;
-			}
-
-			$this->setJdFromYmd();
-
-			return;
-		}
+    /** @var int[] Convert GEDCOM month names to month numbers  */
+    public static $MONTH_ABBREV = array('' => 0, 'JAN' => 1, 'FEB' => 2, 'MAR' => 3, 'APR' => 4, 'MAY' => 5, 'JUN' => 6, 'JUL' => 7, 'AUG' => 8, 'SEP' => 9, 'OCT' => 10, 'NOV' => 11, 'DEC' => 12);
+
+    /** @var string[] Convert numbers to/from roman numerals */
+    protected static $roman_numerals = array(1000 => 'M', 900 => 'CM', 500 => 'D', 400 => 'CD', 100 => 'C', 90 => 'XC', 50 => 'L', 40 => 'XL', 10 => 'X', 9 => 'IX', 5 => 'V', 4 => 'IV', 1 => 'I');
+
+    /** @var CalendarInterface The calendar system used to represent this date */
+    protected $calendar;
+
+    /** @var int Year number  */
+    public $y;
+
+    /** @var int Month number  */
+    public $m;
+
+    /** @var int Day number  */
+    public $d;
+
+    /** @var int Earliest Julian day number (start of month/year for imprecise dates) */
+    public $minJD;
+
+    /** @var int Latest Julian day number (end of month/year for imprecise dates) */
+    public $maxJD;
+
+    /**
+     * Create a date from either:
+     * a Julian day number
+     * day/month/year strings from a GEDCOM date
+     * another CalendarDate object
+     *
+     * @param array|int|CalendarDate $date
+     */
+    public function __construct($date) {
+        // Construct from an integer (a julian day number)
+        if (is_integer($date)) {
+            $this->minJD                       = $date;
+            $this->maxJD                       = $date;
+            list($this->y, $this->m, $this->d) = $this->calendar->jdToYmd($date);
+
+            return;
+        }
+
+        // Construct from an array (of three gedcom-style strings: "1900", "FEB", "4")
+        if (is_array($date)) {
+            $this->d = (int) $date[2];
+            if (array_key_exists($date[1], static::$MONTH_ABBREV)) {
+                $this->m = static::$MONTH_ABBREV[$date[1]];
+            } else {
+                $this->m = 0;
+                $this->d = 0;
+            }
+            $this->y = $this->extractYear($date[0]);
+
+            // Our simple lookup table above does not take into account Adar and leap-years.
+            if ($this->m === 6 && $this->calendar instanceof JewishCalendar && !$this->calendar->isLeapYear($this->y)) {
+                $this->m = 7;
+            }
+
+            $this->setJdFromYmd();
+
+            return;
+        }
 
         $this->minJD = $date->minJD;
         $this->maxJD = $date->maxJD;
 
-		// Construct from an equivalent xxxxDate object
-		if (get_class($this) == get_class($date)) {
-			$this->y     = $date->y;
-			$this->m     = $date->m;
-			$this->d     = $date->d;
+        // Construct from an equivalent xxxxDate object
+        if (get_class($this) == get_class($date)) {
+            $this->y     = $date->y;
+            $this->m     = $date->m;
+            $this->d     = $date->d;
 
-			return;
-		}
+            return;
+        }
 
         // Not all dates can be converted
         if (!$this->inValidRange()) {
@@ -117,838 +117,838 @@ 
         }
 
         // ...else construct an inequivalent xxxxDate object
-		if ($date->y == 0) {
-			// Incomplete date - convert on basis of anniversary in current year
-			$today = $date->calendar->jdToYmd(unixtojd());
-			$jd    = $date->calendar->ymdToJd($today[0], $date->m, $date->d == 0 ? $today[2] : $date->d);
-		} else {
-			// Complete date
-			$jd = (int) (($date->maxJD + $date->minJD) / 2);
-		}
-		list($this->y, $this->m, $this->d) = $this->calendar->jdToYmd($jd);
-		// New date has same precision as original date
-		if ($date->y == 0) {
-			$this->y = 0;
-		}
-		if ($date->m == 0) {
-			$this->m = 0;
-		}
-		if ($date->d == 0) {
-			$this->d = 0;
-		}
-		$this->setJdFromYmd();
-	}
-
-	/**
-	 * Is the current year a leap year?
-	 *
-	 * @return bool
-	 */
-	public function isLeapYear() {
-		return $this->calendar->isLeapYear($this->y);
-	}
-
-	/**
-	 * Set the object’s Julian day number from a potentially incomplete year/month/day
-	 */
-	public function setJdFromYmd() {
-		if ($this->y == 0) {
-			$this->minJD = 0;
-			$this->maxJD = 0;
-		} elseif ($this->m == 0) {
-			$this->minJD = $this->calendar->ymdToJd($this->y, 1, 1);
-			$this->maxJD = $this->calendar->ymdToJd($this->nextYear($this->y), 1, 1) - 1;
-		} elseif ($this->d == 0) {
-			list($ny, $nm) = $this->nextMonth();
-			$this->minJD   = $this->calendar->ymdToJd($this->y, $this->m, 1);
-			$this->maxJD   = $this->calendar->ymdToJd($ny, $nm, 1) - 1;
-		} else {
-			$this->minJD = $this->calendar->ymdToJd($this->y, $this->m, $this->d);
-			$this->maxJD = $this->minJD;
-		}
-	}
-
-	/**
-	 * Full month name in nominative case.
-	 *
-	 * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
-	 *
-	 * @param int  $month_number
-	 * @param bool $leap_year    Some calendars use leap months
-	 *
-	 * @return string
-	 */
-	public static function monthNameNominativeCase($month_number, $leap_year) {
-		static $translated_month_names;
-
-		if ($translated_month_names === null) {
-			$translated_month_names = array(
-				0  => '',
-				1  => I18N::translateContext('NOMINATIVE', 'January'),
-				2  => I18N::translateContext('NOMINATIVE', 'February'),
-				3  => I18N::translateContext('NOMINATIVE', 'March'),
-				4  => I18N::translateContext('NOMINATIVE', 'April'),
-				5  => I18N::translateContext('NOMINATIVE', 'May'),
-				6  => I18N::translateContext('NOMINATIVE', 'June'),
-				7  => I18N::translateContext('NOMINATIVE', 'July'),
-				8  => I18N::translateContext('NOMINATIVE', 'August'),
-				9  => I18N::translateContext('NOMINATIVE', 'September'),
-				10 => I18N::translateContext('NOMINATIVE', 'October'),
-				11 => I18N::translateContext('NOMINATIVE', 'November'),
-				12 => I18N::translateContext('NOMINATIVE', 'December'),
-			);
-		}
-
-		return $translated_month_names[$month_number];
-	}
-
-	/**
-	 * Full month name in genitive case.
-	 *
-	 * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
-	 *
-	 * @param int  $month_number
-	 * @param bool $leap_year    Some calendars use leap months
-	 *
-	 * @return string
-	 */
-	protected function monthNameGenitiveCase($month_number, $leap_year) {
-		static $translated_month_names;
-
-		if ($translated_month_names === null) {
-			$translated_month_names = array(
-				0  => '',
-				1  => I18N::translateContext('GENITIVE', 'January'),
-				2  => I18N::translateContext('GENITIVE', 'February'),
-				3  => I18N::translateContext('GENITIVE', 'March'),
-				4  => I18N::translateContext('GENITIVE', 'April'),
-				5  => I18N::translateContext('GENITIVE', 'May'),
-				6  => I18N::translateContext('GENITIVE', 'June'),
-				7  => I18N::translateContext('GENITIVE', 'July'),
-				8  => I18N::translateContext('GENITIVE', 'August'),
-				9  => I18N::translateContext('GENITIVE', 'September'),
-				10 => I18N::translateContext('GENITIVE', 'October'),
-				11 => I18N::translateContext('GENITIVE', 'November'),
-				12 => I18N::translateContext('GENITIVE', 'December'),
-			);
-		}
-
-		return $translated_month_names[$month_number];
-	}
-
-	/**
-	 * Full month name in locative case.
-	 *
-	 * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
-	 *
-	 * @param int  $month_number
-	 * @param bool $leap_year    Some calendars use leap months
-	 *
-	 * @return string
-	 */
-	protected function monthNameLocativeCase($month_number, $leap_year) {
-		static $translated_month_names;
-
-		if ($translated_month_names === null) {
-			$translated_month_names = array(
-				0  => '',
-				1  => I18N::translateContext('LOCATIVE', 'January'),
-				2  => I18N::translateContext('LOCATIVE', 'February'),
-				3  => I18N::translateContext('LOCATIVE', 'March'),
-				4  => I18N::translateContext('LOCATIVE', 'April'),
-				5  => I18N::translateContext('LOCATIVE', 'May'),
-				6  => I18N::translateContext('LOCATIVE', 'June'),
-				7  => I18N::translateContext('LOCATIVE', 'July'),
-				8  => I18N::translateContext('LOCATIVE', 'August'),
-				9  => I18N::translateContext('LOCATIVE', 'September'),
-				10 => I18N::translateContext('LOCATIVE', 'October'),
-				11 => I18N::translateContext('LOCATIVE', 'November'),
-				12 => I18N::translateContext('LOCATIVE', 'December'),
-			);
-		}
-
-		return $translated_month_names[$month_number];
-	}
-
-	/**
-	 * Full month name in instrumental case.
-	 *
-	 * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
-	 *
-	 * @param int  $month_number
-	 * @param bool $leap_year    Some calendars use leap months
-	 *
-	 * @return string
-	 */
-	protected function monthNameInstrumentalCase($month_number, $leap_year) {
-		static $translated_month_names;
-
-		if ($translated_month_names === null) {
-			$translated_month_names = array(
-				0  => '',
-				1  => I18N::translateContext('INSTRUMENTAL', 'January'),
-				2  => I18N::translateContext('INSTRUMENTAL', 'February'),
-				3  => I18N::translateContext('INSTRUMENTAL', 'March'),
-				4  => I18N::translateContext('INSTRUMENTAL', 'April'),
-				5  => I18N::translateContext('INSTRUMENTAL', 'May'),
-				6  => I18N::translateContext('INSTRUMENTAL', 'June'),
-				7  => I18N::translateContext('INSTRUMENTAL', 'July'),
-				8  => I18N::translateContext('INSTRUMENTAL', 'August'),
-				9  => I18N::translateContext('INSTRUMENTAL', 'September'),
-				10 => I18N::translateContext('INSTRUMENTAL', 'October'),
-				11 => I18N::translateContext('INSTRUMENTAL', 'November'),
-				12 => I18N::translateContext('INSTRUMENTAL', 'December'),
-			);
-		}
-
-		return $translated_month_names[$month_number];
-	}
-
-	/**
-	 * Abbreviated month name
-	 *
-	 * @param int  $month_number
-	 * @param bool $leap_year    Some calendars use leap months
-	 *
-	 * @return string
-	 */
-	protected function monthNameAbbreviated($month_number, $leap_year) {
-		static $translated_month_names;
-
-		if ($translated_month_names === null) {
-			$translated_month_names = array(
-				0  => '',
-				1  => I18N::translateContext('Abbreviation for January', 'Jan'),
-				2  => I18N::translateContext('Abbreviation for February', 'Feb'),
-				3  => I18N::translateContext('Abbreviation for March', 'Mar'),
-				4  => I18N::translateContext('Abbreviation for April', 'Apr'),
-				5  => I18N::translateContext('Abbreviation for May', 'May'),
-				6  => I18N::translateContext('Abbreviation for June', 'Jun'),
-				7  => I18N::translateContext('Abbreviation for July', 'Jul'),
-				8  => I18N::translateContext('Abbreviation for August', 'Aug'),
-				9  => I18N::translateContext('Abbreviation for September', 'Sep'),
-				10 => I18N::translateContext('Abbreviation for October', 'Oct'),
-				11 => I18N::translateContext('Abbreviation for November', 'Nov'),
-				12 => I18N::translateContext('Abbreviation for December', 'Dec'),
-			);
-		}
-
-		return $translated_month_names[$month_number];
-	}
-
-	/**
-	 * Full day of th eweek
-	 *
-	 * @param int $day_number
-	 *
-	 * @return string
-	 */
-	public function dayNames($day_number) {
-		static $translated_day_names;
-
-		if ($translated_day_names === null) {
-			$translated_day_names = array(
-				0  => I18N::translate('Monday'),
-				1  => I18N::translate('Tuesday'),
-				2  => I18N::translate('Wednesday'),
-				3  => I18N::translate('Thursday'),
-				4  => I18N::translate('Friday'),
-				5  => I18N::translate('Saturday'),
-				6  => I18N::translate('Sunday'),
-			);
-		}
-
-		return $translated_day_names[$day_number];
-	}
-
-	/**
-	 * Abbreviated day of the week
-	 *
-	 * @param int $day_number
-	 *
-	 * @return string
-	 */
-	protected function dayNamesAbbreviated($day_number) {
-		static $translated_day_names;
-
-		if ($translated_day_names === null) {
-			$translated_day_names = array(
-				0  => /* I18N: abbreviation for Monday */ I18N::translate('Mon'),
-				1  => /* I18N: abbreviation for Tuesday */ I18N::translate('Tue'),
-				2  => /* I18N: abbreviation for Wednesday */ I18N::translate('Wed'),
-				3  => /* I18N: abbreviation for Thursday */ I18N::translate('Thu'),
-				4  => /* I18N: abbreviation for Friday */ I18N::translate('Fri'),
-				5  => /* I18N: abbreviation for Saturday */ I18N::translate('Sat'),
-				6  => /* I18N: abbreviation for Sunday */ I18N::translate('Sun'),
-			);
-		}
-
-		return $translated_day_names[$day_number];
-	}
-
-	/**
-	 * Most years are 1 more than the previous, but not always (e.g. 1BC->1AD)
-	 *
-	 * @param int $year
-	 *
-	 * @return int
-	 */
-	protected function nextYear($year) {
-		return $year + 1;
-	}
-
-	/**
-	 * Calendars that use suffixes, etc. (e.g. “B.C.”) or OS/NS notation should redefine this.
-	 *
-	 * @param string $year
-	 *
-	 * @return int
-	 */
-	protected function extractYear($year) {
-		return (int) $year;
-	}
-
-	/**
-	 * Compare two dates, for sorting
-	 *
-	 * @param CalendarDate $d1
-	 * @param CalendarDate $d2
-	 *
-	 * @return int
-	 */
-	public static function compare(CalendarDate $d1, CalendarDate $d2) {
-		if ($d1->maxJD < $d2->minJD) {
-			return -1;
-		} elseif ($d2->maxJD < $d1->minJD) {
-			return 1;
-		} else {
-			return 0;
-		}
-	}
-
-	/**
-	 * How long between an event and a given julian day
-	 * Return result as either a number of years or
-	 * a gedcom-style age string.
-	 *
-	 * @todo JewishDate needs to redefine this to cope with leap months
-	 *
-	 * @param bool $full             true=gedcom style, false=just years
-	 * @param int $jd                date for calculation
-	 * @param bool $warn_on_negative show a warning triangle for negative ages
-	 *
-	 * @return string
-	 */
-	public function getAge($full, $jd, $warn_on_negative = true) {
-		if ($this->y == 0 || $jd == 0) {
-			return $full ? '' : '0';
-		}
-		if ($this->minJD < $jd && $this->maxJD > $jd) {
-			return $full ? '' : '0';
-		}
-		if ($this->minJD == $jd) {
-			return $full ? '' : '0';
-		}
-		if ($warn_on_negative && $jd < $this->minJD) {
-			return '<i class="icon-warning"></i>';
-		}
-		list($y, $m, $d) = $this->calendar->jdToYmd($jd);
-		$dy              = $y - $this->y;
-		$dm              = $m - max($this->m, 1);
-		$dd              = $d - max($this->d, 1);
-		if ($dd < 0) {
-			$dm--;
-		}
-		if ($dm < 0) {
-			$dm += $this->calendar->monthsInYear();
-			$dy--;
-		}
-		// Not a full age? Then just the years
-		if (!$full) {
-			return $dy;
-		}
-		// Age in years?
-		if ($dy > 1) {
-			return $dy . 'y';
-		}
-		$dm += $dy * $this->calendar->monthsInYear();
-		// Age in months?
-		if ($dm > 1) {
-			return $dm . 'm';
-		}
-
-		// Age in days?
-		return ($jd - $this->minJD) . 'd';
-	}
-
-	/**
-	 * Convert a date from one calendar to another.
-	 *
-	 * @param string $calendar
-	 *
-	 * @return CalendarDate
-	 */
-	public function convertToCalendar($calendar) {
-		switch ($calendar) {
-		case 'gregorian':
-			return new GregorianDate($this);
-		case 'julian':
-			return new JulianDate($this);
-		case 'jewish':
-			return new JewishDate($this);
-		case 'french':
-			return new FrenchDate($this);
-		case 'hijri':
-			return new HijriDate($this);
-		case 'jalali':
-			return new JalaliDate($this);
-		default:
-			return $this;
-		}
-	}
-
-	/**
-	 * Is this date within the valid range of the calendar
-	 *
-	 * @return bool
-	 */
-	public function inValidRange() {
-		return $this->minJD >= $this->calendar->jdStart() && $this->maxJD <= $this->calendar->jdEnd();
-	}
-
-	/**
-	 * How many months in a year
-	 *
-	 * @return int
-	 */
-	public function monthsInYear() {
-		return $this->calendar->monthsInYear();
-	}
-
-	/**
-	 * How many days in the current month
-	 *
-	 * @return int
-	 */
-	public function daysInMonth() {
-		try {
-			return $this->calendar->daysInMonth($this->y, $this->m);
-		} catch (\InvalidArgumentException $ex) {
-			// calendar.php calls this with "DD MMM" dates, for which we cannot calculate
-			// the length of a month. Should we validate this before calling this function?
-			return 0;
-		}
-	}
-
-	/**
-	 * How many days in the current week
-	 *
-	 * @return int
-	 */
-	public function daysInWeek() {
-		return $this->calendar->daysInWeek();
-	}
-
-	/**
-	 * Format a date, using similar codes to the PHP date() function.
-	 *
-	 * @param string $format    See http://php.net/date
-	 * @param string $qualifier GEDCOM qualifier, so we can choose the right case for the month name.
-	 *
-	 * @return string
-	 */
-	public function format($format, $qualifier = '') {
-		// Don’t show exact details for inexact dates
-		if (!$this->d) {
-			// The comma is for US "M D, Y" dates
-			$format = preg_replace('/%[djlDNSwz][,]?/', '', $format);
-		}
-		if (!$this->m) {
-			$format = str_replace(array('%F', '%m', '%M', '%n', '%t'), '', $format);
-		}
-		if (!$this->y) {
-			$format = str_replace(array('%t', '%L', '%G', '%y', '%Y'), '', $format);
-		}
-		// If we’ve trimmed the format, also trim the punctuation
-		if (!$this->d || !$this->m || !$this->y) {
-			$format = trim($format, ',. ;/-');
-		}
-		if ($this->d && preg_match('/%[djlDNSwz]/', $format)) {
-			// If we have a day-number *and* we are being asked to display it, then genitive
-			$case = 'GENITIVE';
-		} else {
-			switch ($qualifier) {
-			case 'TO':
-			case 'ABT':
-			case 'FROM':
-				$case = 'GENITIVE';
-				break;
-			case 'AFT':
-				$case = 'LOCATIVE';
-				break;
-			case 'BEF':
-			case 'BET':
-			case 'AND':
-				$case = 'INSTRUMENTAL';
-				break;
-			case '':
-			case 'INT':
-			case 'EST':
-			case 'CAL':
-			default: // There shouldn't be any other options...
-				$case = 'NOMINATIVE';
-				break;
-			}
-		}
-		// Build up the formatted date, character at a time
-		preg_match_all('/%[^%]/', $format, $matches);
-		foreach ($matches[0] as $match) {
-			switch ($match) {
-			case '%d':
-				$format = str_replace($match, $this->formatDayZeros(), $format);
-				break;
-			case '%j':
-				$format = str_replace($match, $this->formatDay(), $format);
-				break;
-			case '%l':
-				$format = str_replace($match, $this->formatLongWeekday(), $format);
-				break;
-			case '%D':
-				$format = str_replace($match, $this->formatShortWeekday(), $format);
-				break;
-			case '%N':
-				$format = str_replace($match, $this->formatIsoWeekday(), $format);
-				break;
-			case '%w':
-				$format = str_replace($match, $this->formatNumericWeekday(), $format);
-				break;
-			case '%z':
-				$format = str_replace($match, $this->formatDayOfYear(), $format);
-				break;
-			case '%F':
-				$format = str_replace($match, $this->formatLongMonth($case), $format);
-				break;
-			case '%m':
-				$format = str_replace($match, $this->formatMonthZeros(), $format);
-				break;
-			case '%M':
-				$format = str_replace($match, $this->formatShortMonth(), $format);
-				break;
-			case '%n':
-				$format = str_replace($match, $this->formatMonth(), $format);
-				break;
-			case '%t':
-				$format = str_replace($match, $this->daysInMonth(), $format);
-				break;
-			case '%L':
-				$format = str_replace($match, (int) $this->isLeapYear(), $format);
-				break;
-			case '%Y':
-				$format = str_replace($match, $this->formatLongYear(), $format);
-				break;
-			case '%y':
-				$format = str_replace($match, $this->formatShortYear(), $format);
-				break;
-				// These 4 extensions are useful for re-formatting gedcom dates.
-			case '%@':
-				$format = str_replace($match, $this->calendar->gedcomCalendarEscape(), $format);
-				break;
-			case '%A':
-				$format = str_replace($match, $this->formatGedcomDay(), $format);
-				break;
-			case '%O':
-				$format = str_replace($match, $this->formatGedcomMonth(), $format);
-				break;
-			case '%E':
-				$format = str_replace($match, $this->formatGedcomYear(), $format);
-				break;
-			}
-		}
-
-		return $format;
-	}
-
-	/**
-	 * Generate the %d format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatDayZeros() {
-		if ($this->d > 9) {
-			return I18N::digits($this->d);
-		} else {
-			return I18N::digits('0' . $this->d);
-		}
-	}
-
-	/**
-	 * Generate the %j format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatDay() {
-		return I18N::digits($this->d);
-	}
-
-	/**
-	 * Generate the %l format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatLongWeekday() {
-		return $this->dayNames($this->minJD % $this->calendar->daysInWeek());
-	}
-
-	/**
-	 * Generate the %D format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatShortWeekday() {
-		return $this->dayNamesAbbreviated($this->minJD % $this->calendar->daysInWeek());
-	}
-
-	/**
-	 * Generate the %N format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatIsoWeekday() {
-		return I18N::digits($this->minJD % 7 + 1);
-	}
-
-	/**
-	 * Generate the %w format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatNumericWeekday() {
-		return I18N::digits(($this->minJD + 1) % $this->calendar->daysInWeek());
-	}
-
-	/**
-	 * Generate the %z format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatDayOfYear() {
-		return I18N::digits($this->minJD - $this->calendar->ymdToJd($this->y, 1, 1));
-	}
-
-	/**
-	 * Generate the %n format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatMonth() {
-		return I18N::digits($this->m);
-	}
-
-	/**
-	 * Generate the %m format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatMonthZeros() {
-		if ($this->m > 9) {
-			return I18N::digits($this->m);
-		} else {
-			return I18N::digits('0' . $this->m);
-		}
-	}
-
-	/**
-	 * Generate the %F format for a date.
-	 *
-	 * @param string $case Which grammatical case shall we use
-	 *
-	 * @return string
-	 */
-	protected function formatLongMonth($case = 'NOMINATIVE') {
-		switch ($case) {
-		case 'GENITIVE':
-			return $this->monthNameGenitiveCase($this->m, $this->isLeapYear());
-		case 'NOMINATIVE':
-			return $this->monthNameNominativeCase($this->m, $this->isLeapYear());
-		case 'LOCATIVE':
-			return $this->monthNameLocativeCase($this->m, $this->isLeapYear());
-		case 'INSTRUMENTAL':
-			return $this->monthNameInstrumentalCase($this->m, $this->isLeapYear());
-		default:
-			throw new \InvalidArgumentException($case);
-		}
-	}
-
-	/**
-	 * Generate the %M format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatShortMonth() {
-		return $this->monthNameAbbreviated($this->m, $this->isLeapYear());
-	}
-
-	/**
-	 * Generate the %y format for a date.
-	 *
-	 * NOTE Short year is NOT a 2-digit year. It is for calendars such as hebrew
-	 * which have a 3-digit form of 4-digit years.
-	 *
-	 * @return string
-	 */
-	protected function formatShortYear() {
-		return $this->formatLongYear();
-	}
-
-	/**
-	 * Generate the %A format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatGedcomDay() {
-		if ($this->d == 0) {
-			return '';
-		} else {
-			return sprintf('%02d', $this->d);
-		}
-	}
-
-	/**
-	 * Generate the %O format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatGedcomMonth() {
-		// Our simple lookup table doesn't work correctly for Adar on leap years
-		if ($this->m == 7 && $this->calendar instanceof JewishCalendar && !$this->calendar->isLeapYear($this->y)) {
-			return 'ADR';
-		} else {
-			return array_search($this->m, static::$MONTH_ABBREV);
-		}
-	}
-
-	/**
-	 * Generate the %E format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatGedcomYear() {
-		if ($this->y == 0) {
-			return '';
-		} else {
-			return sprintf('%04d', $this->y);
-		}
-	}
-
-	/**
-	 * Generate the %Y format for a date.
-	 *
-	 * @return string
-	 */
-	protected function formatLongYear() {
-		return I18N::digits($this->y);
-	}
-
-	/**
-	 * Which months follows this one? Calendars with leap-months should provide their own implementation.
-	 *
-	 * @return int[]
-	 */
-	protected function nextMonth() {
-		return array($this->m === $this->calendar->monthsInYear() ? $this->nextYear($this->y) : $this->y, ($this->m % $this->calendar->monthsInYear()) + 1);
-	}
-
-	/**
-	 * Convert a decimal number to roman numerals
-	 *
-	 * @param int $number
-	 *
-	 * @return string
-	 */
-	protected function numberToRomanNumerals($number) {
-		if ($number < 1) {
-			// Cannot convert zero/negative numbers
-			return (string) $number;
-		}
-		$roman = '';
-		foreach (self::$roman_numerals as $key => $value) {
-			while ($number >= $key) {
-				$roman .= $value;
-				$number -= $key;
-			}
-		}
-
-		return $roman;
-	}
-
-	/**
-	 * Convert a roman numeral to decimal
-	 *
-	 * @param string $roman
-	 *
-	 * @return int
-	 */
-	protected function romanNumeralsToNumber($roman) {
-		$num = 0;
-		foreach (self::$roman_numerals as $key => $value) {
-			if (strpos($roman, $value) === 0) {
-				$num += $key;
-				$roman = substr($roman, strlen($value));
-			}
-		}
-
-		return $num;
-	}
-
-	/**
-	 * Get today’s date in the current calendar.
-	 *
-	 * @return int[]
-	 */
-	public function todayYmd() {
-		return $this->calendar->jdToYmd(unixtojd());
-	}
-
-	/**
-	 * Convert to today’s date.
-	 *
-	 * @return CalendarDate
-	 */
-	public function today() {
-		$tmp    = clone $this;
-		$ymd    = $tmp->todayYmd();
-		$tmp->y = $ymd[0];
-		$tmp->m = $ymd[1];
-		$tmp->d = $ymd[2];
-		$tmp->setJdFromYmd();
-
-		return $tmp;
-	}
-
-	/**
-	 * Create a URL that links this date to the WT calendar
-	 *
-	 * @param string $date_format
-	 *
-	 * @return string
-	 */
-	public function calendarUrl($date_format) {
-		if (strpbrk($date_format, 'dDj') && $this->d) {
-			// If the format includes a day, and the date also includes a day, then use the day view
-			$view = 'day';
-		} elseif (strpbrk($date_format, 'FMmn') && $this->m) {
-			// If the format includes a month, and the date also includes a month, then use the month view
-			$view = 'month';
-		} else {
-			// Use the year view
-			$view = 'year';
-		}
-
-		return
-			'calendar.php?cal=' . rawurlencode($this->calendar->gedcomCalendarEscape()) .
-			'&amp;year=' . $this->formatGedcomYear() .
-			'&amp;month=' . $this->formatGedcomMonth() .
-			'&amp;day=' . $this->formatGedcomDay() .
-			'&amp;view=' . $view;
-	}
+        if ($date->y == 0) {
+            // Incomplete date - convert on basis of anniversary in current year
+            $today = $date->calendar->jdToYmd(unixtojd());
+            $jd    = $date->calendar->ymdToJd($today[0], $date->m, $date->d == 0 ? $today[2] : $date->d);
+        } else {
+            // Complete date
+            $jd = (int) (($date->maxJD + $date->minJD) / 2);
+        }
+        list($this->y, $this->m, $this->d) = $this->calendar->jdToYmd($jd);
+        // New date has same precision as original date
+        if ($date->y == 0) {
+            $this->y = 0;
+        }
+        if ($date->m == 0) {
+            $this->m = 0;
+        }
+        if ($date->d == 0) {
+            $this->d = 0;
+        }
+        $this->setJdFromYmd();
+    }
+
+    /**
+     * Is the current year a leap year?
+     *
+     * @return bool
+     */
+    public function isLeapYear() {
+        return $this->calendar->isLeapYear($this->y);
+    }
+
+    /**
+     * Set the object’s Julian day number from a potentially incomplete year/month/day
+     */
+    public function setJdFromYmd() {
+        if ($this->y == 0) {
+            $this->minJD = 0;
+            $this->maxJD = 0;
+        } elseif ($this->m == 0) {
+            $this->minJD = $this->calendar->ymdToJd($this->y, 1, 1);
+            $this->maxJD = $this->calendar->ymdToJd($this->nextYear($this->y), 1, 1) - 1;
+        } elseif ($this->d == 0) {
+            list($ny, $nm) = $this->nextMonth();
+            $this->minJD   = $this->calendar->ymdToJd($this->y, $this->m, 1);
+            $this->maxJD   = $this->calendar->ymdToJd($ny, $nm, 1) - 1;
+        } else {
+            $this->minJD = $this->calendar->ymdToJd($this->y, $this->m, $this->d);
+            $this->maxJD = $this->minJD;
+        }
+    }
+
+    /**
+     * Full month name in nominative case.
+     *
+     * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
+     *
+     * @param int  $month_number
+     * @param bool $leap_year    Some calendars use leap months
+     *
+     * @return string
+     */
+    public static function monthNameNominativeCase($month_number, $leap_year) {
+        static $translated_month_names;
+
+        if ($translated_month_names === null) {
+            $translated_month_names = array(
+                0  => '',
+                1  => I18N::translateContext('NOMINATIVE', 'January'),
+                2  => I18N::translateContext('NOMINATIVE', 'February'),
+                3  => I18N::translateContext('NOMINATIVE', 'March'),
+                4  => I18N::translateContext('NOMINATIVE', 'April'),
+                5  => I18N::translateContext('NOMINATIVE', 'May'),
+                6  => I18N::translateContext('NOMINATIVE', 'June'),
+                7  => I18N::translateContext('NOMINATIVE', 'July'),
+                8  => I18N::translateContext('NOMINATIVE', 'August'),
+                9  => I18N::translateContext('NOMINATIVE', 'September'),
+                10 => I18N::translateContext('NOMINATIVE', 'October'),
+                11 => I18N::translateContext('NOMINATIVE', 'November'),
+                12 => I18N::translateContext('NOMINATIVE', 'December'),
+            );
+        }
+
+        return $translated_month_names[$month_number];
+    }
+
+    /**
+     * Full month name in genitive case.
+     *
+     * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
+     *
+     * @param int  $month_number
+     * @param bool $leap_year    Some calendars use leap months
+     *
+     * @return string
+     */
+    protected function monthNameGenitiveCase($month_number, $leap_year) {
+        static $translated_month_names;
+
+        if ($translated_month_names === null) {
+            $translated_month_names = array(
+                0  => '',
+                1  => I18N::translateContext('GENITIVE', 'January'),
+                2  => I18N::translateContext('GENITIVE', 'February'),
+                3  => I18N::translateContext('GENITIVE', 'March'),
+                4  => I18N::translateContext('GENITIVE', 'April'),
+                5  => I18N::translateContext('GENITIVE', 'May'),
+                6  => I18N::translateContext('GENITIVE', 'June'),
+                7  => I18N::translateContext('GENITIVE', 'July'),
+                8  => I18N::translateContext('GENITIVE', 'August'),
+                9  => I18N::translateContext('GENITIVE', 'September'),
+                10 => I18N::translateContext('GENITIVE', 'October'),
+                11 => I18N::translateContext('GENITIVE', 'November'),
+                12 => I18N::translateContext('GENITIVE', 'December'),
+            );
+        }
+
+        return $translated_month_names[$month_number];
+    }
+
+    /**
+     * Full month name in locative case.
+     *
+     * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
+     *
+     * @param int  $month_number
+     * @param bool $leap_year    Some calendars use leap months
+     *
+     * @return string
+     */
+    protected function monthNameLocativeCase($month_number, $leap_year) {
+        static $translated_month_names;
+
+        if ($translated_month_names === null) {
+            $translated_month_names = array(
+                0  => '',
+                1  => I18N::translateContext('LOCATIVE', 'January'),
+                2  => I18N::translateContext('LOCATIVE', 'February'),
+                3  => I18N::translateContext('LOCATIVE', 'March'),
+                4  => I18N::translateContext('LOCATIVE', 'April'),
+                5  => I18N::translateContext('LOCATIVE', 'May'),
+                6  => I18N::translateContext('LOCATIVE', 'June'),
+                7  => I18N::translateContext('LOCATIVE', 'July'),
+                8  => I18N::translateContext('LOCATIVE', 'August'),
+                9  => I18N::translateContext('LOCATIVE', 'September'),
+                10 => I18N::translateContext('LOCATIVE', 'October'),
+                11 => I18N::translateContext('LOCATIVE', 'November'),
+                12 => I18N::translateContext('LOCATIVE', 'December'),
+            );
+        }
+
+        return $translated_month_names[$month_number];
+    }
+
+    /**
+     * Full month name in instrumental case.
+     *
+     * We put these in the base class, to save duplicating it in the Julian and Gregorian calendars.
+     *
+     * @param int  $month_number
+     * @param bool $leap_year    Some calendars use leap months
+     *
+     * @return string
+     */
+    protected function monthNameInstrumentalCase($month_number, $leap_year) {
+        static $translated_month_names;
+
+        if ($translated_month_names === null) {
+            $translated_month_names = array(
+                0  => '',
+                1  => I18N::translateContext('INSTRUMENTAL', 'January'),
+                2  => I18N::translateContext('INSTRUMENTAL', 'February'),
+                3  => I18N::translateContext('INSTRUMENTAL', 'March'),
+                4  => I18N::translateContext('INSTRUMENTAL', 'April'),
+                5  => I18N::translateContext('INSTRUMENTAL', 'May'),
+                6  => I18N::translateContext('INSTRUMENTAL', 'June'),
+                7  => I18N::translateContext('INSTRUMENTAL', 'July'),
+                8  => I18N::translateContext('INSTRUMENTAL', 'August'),
+                9  => I18N::translateContext('INSTRUMENTAL', 'September'),
+                10 => I18N::translateContext('INSTRUMENTAL', 'October'),
+                11 => I18N::translateContext('INSTRUMENTAL', 'November'),
+                12 => I18N::translateContext('INSTRUMENTAL', 'December'),
+            );
+        }
+
+        return $translated_month_names[$month_number];
+    }
+
+    /**
+     * Abbreviated month name
+     *
+     * @param int  $month_number
+     * @param bool $leap_year    Some calendars use leap months
+     *
+     * @return string
+     */
+    protected function monthNameAbbreviated($month_number, $leap_year) {
+        static $translated_month_names;
+
+        if ($translated_month_names === null) {
+            $translated_month_names = array(
+                0  => '',
+                1  => I18N::translateContext('Abbreviation for January', 'Jan'),
+                2  => I18N::translateContext('Abbreviation for February', 'Feb'),
+                3  => I18N::translateContext('Abbreviation for March', 'Mar'),
+                4  => I18N::translateContext('Abbreviation for April', 'Apr'),
+                5  => I18N::translateContext('Abbreviation for May', 'May'),
+                6  => I18N::translateContext('Abbreviation for June', 'Jun'),
+                7  => I18N::translateContext('Abbreviation for July', 'Jul'),
+                8  => I18N::translateContext('Abbreviation for August', 'Aug'),
+                9  => I18N::translateContext('Abbreviation for September', 'Sep'),
+                10 => I18N::translateContext('Abbreviation for October', 'Oct'),
+                11 => I18N::translateContext('Abbreviation for November', 'Nov'),
+                12 => I18N::translateContext('Abbreviation for December', 'Dec'),
+            );
+        }
+
+        return $translated_month_names[$month_number];
+    }
+
+    /**
+     * Full day of th eweek
+     *
+     * @param int $day_number
+     *
+     * @return string
+     */
+    public function dayNames($day_number) {
+        static $translated_day_names;
+
+        if ($translated_day_names === null) {
+            $translated_day_names = array(
+                0  => I18N::translate('Monday'),
+                1  => I18N::translate('Tuesday'),
+                2  => I18N::translate('Wednesday'),
+                3  => I18N::translate('Thursday'),
+                4  => I18N::translate('Friday'),
+                5  => I18N::translate('Saturday'),
+                6  => I18N::translate('Sunday'),
+            );
+        }
+
+        return $translated_day_names[$day_number];
+    }
+
+    /**
+     * Abbreviated day of the week
+     *
+     * @param int $day_number
+     *
+     * @return string
+     */
+    protected function dayNamesAbbreviated($day_number) {
+        static $translated_day_names;
+
+        if ($translated_day_names === null) {
+            $translated_day_names = array(
+                0  => /* I18N: abbreviation for Monday */ I18N::translate('Mon'),
+                1  => /* I18N: abbreviation for Tuesday */ I18N::translate('Tue'),
+                2  => /* I18N: abbreviation for Wednesday */ I18N::translate('Wed'),
+                3  => /* I18N: abbreviation for Thursday */ I18N::translate('Thu'),
+                4  => /* I18N: abbreviation for Friday */ I18N::translate('Fri'),
+                5  => /* I18N: abbreviation for Saturday */ I18N::translate('Sat'),
+                6  => /* I18N: abbreviation for Sunday */ I18N::translate('Sun'),
+            );
+        }
+
+        return $translated_day_names[$day_number];
+    }
+
+    /**
+     * Most years are 1 more than the previous, but not always (e.g. 1BC->1AD)
+     *
+     * @param int $year
+     *
+     * @return int
+     */
+    protected function nextYear($year) {
+        return $year + 1;
+    }
+
+    /**
+     * Calendars that use suffixes, etc. (e.g. “B.C.”) or OS/NS notation should redefine this.
+     *
+     * @param string $year
+     *
+     * @return int
+     */
+    protected function extractYear($year) {
+        return (int) $year;
+    }
+
+    /**
+     * Compare two dates, for sorting
+     *
+     * @param CalendarDate $d1
+     * @param CalendarDate $d2
+     *
+     * @return int
+     */
+    public static function compare(CalendarDate $d1, CalendarDate $d2) {
+        if ($d1->maxJD < $d2->minJD) {
+            return -1;
+        } elseif ($d2->maxJD < $d1->minJD) {
+            return 1;
+        } else {
+            return 0;
+        }
+    }
+
+    /**
+     * How long between an event and a given julian day
+     * Return result as either a number of years or
+     * a gedcom-style age string.
+     *
+     * @todo JewishDate needs to redefine this to cope with leap months
+     *
+     * @param bool $full             true=gedcom style, false=just years
+     * @param int $jd                date for calculation
+     * @param bool $warn_on_negative show a warning triangle for negative ages
+     *
+     * @return string
+     */
+    public function getAge($full, $jd, $warn_on_negative = true) {
+        if ($this->y == 0 || $jd == 0) {
+            return $full ? '' : '0';
+        }
+        if ($this->minJD < $jd && $this->maxJD > $jd) {
+            return $full ? '' : '0';
+        }
+        if ($this->minJD == $jd) {
+            return $full ? '' : '0';
+        }
+        if ($warn_on_negative && $jd < $this->minJD) {
+            return '<i class="icon-warning"></i>';
+        }
+        list($y, $m, $d) = $this->calendar->jdToYmd($jd);
+        $dy              = $y - $this->y;
+        $dm              = $m - max($this->m, 1);
+        $dd              = $d - max($this->d, 1);
+        if ($dd < 0) {
+            $dm--;
+        }
+        if ($dm < 0) {
+            $dm += $this->calendar->monthsInYear();
+            $dy--;
+        }
+        // Not a full age? Then just the years
+        if (!$full) {
+            return $dy;
+        }
+        // Age in years?
+        if ($dy > 1) {
+            return $dy . 'y';
+        }
+        $dm += $dy * $this->calendar->monthsInYear();
+        // Age in months?
+        if ($dm > 1) {
+            return $dm . 'm';
+        }
+
+        // Age in days?
+        return ($jd - $this->minJD) . 'd';
+    }
+
+    /**
+     * Convert a date from one calendar to another.
+     *
+     * @param string $calendar
+     *
+     * @return CalendarDate
+     */
+    public function convertToCalendar($calendar) {
+        switch ($calendar) {
+        case 'gregorian':
+            return new GregorianDate($this);
+        case 'julian':
+            return new JulianDate($this);
+        case 'jewish':
+            return new JewishDate($this);
+        case 'french':
+            return new FrenchDate($this);
+        case 'hijri':
+            return new HijriDate($this);
+        case 'jalali':
+            return new JalaliDate($this);
+        default:
+            return $this;
+        }
+    }
+
+    /**
+     * Is this date within the valid range of the calendar
+     *
+     * @return bool
+     */
+    public function inValidRange() {
+        return $this->minJD >= $this->calendar->jdStart() && $this->maxJD <= $this->calendar->jdEnd();
+    }
+
+    /**
+     * How many months in a year
+     *
+     * @return int
+     */
+    public function monthsInYear() {
+        return $this->calendar->monthsInYear();
+    }
+
+    /**
+     * How many days in the current month
+     *
+     * @return int
+     */
+    public function daysInMonth() {
+        try {
+            return $this->calendar->daysInMonth($this->y, $this->m);
+        } catch (\InvalidArgumentException $ex) {
+            // calendar.php calls this with "DD MMM" dates, for which we cannot calculate
+            // the length of a month. Should we validate this before calling this function?
+            return 0;
+        }
+    }
+
+    /**
+     * How many days in the current week
+     *
+     * @return int
+     */
+    public function daysInWeek() {
+        return $this->calendar->daysInWeek();
+    }
+
+    /**
+     * Format a date, using similar codes to the PHP date() function.
+     *
+     * @param string $format    See http://php.net/date
+     * @param string $qualifier GEDCOM qualifier, so we can choose the right case for the month name.
+     *
+     * @return string
+     */
+    public function format($format, $qualifier = '') {
+        // Don’t show exact details for inexact dates
+        if (!$this->d) {
+            // The comma is for US "M D, Y" dates
+            $format = preg_replace('/%[djlDNSwz][,]?/', '', $format);
+        }
+        if (!$this->m) {
+            $format = str_replace(array('%F', '%m', '%M', '%n', '%t'), '', $format);
+        }
+        if (!$this->y) {
+            $format = str_replace(array('%t', '%L', '%G', '%y', '%Y'), '', $format);
+        }
+        // If we’ve trimmed the format, also trim the punctuation
+        if (!$this->d || !$this->m || !$this->y) {
+            $format = trim($format, ',. ;/-');
+        }
+        if ($this->d && preg_match('/%[djlDNSwz]/', $format)) {
+            // If we have a day-number *and* we are being asked to display it, then genitive
+            $case = 'GENITIVE';
+        } else {
+            switch ($qualifier) {
+            case 'TO':
+            case 'ABT':
+            case 'FROM':
+                $case = 'GENITIVE';
+                break;
+            case 'AFT':
+                $case = 'LOCATIVE';
+                break;
+            case 'BEF':
+            case 'BET':
+            case 'AND':
+                $case = 'INSTRUMENTAL';
+                break;
+            case '':
+            case 'INT':
+            case 'EST':
+            case 'CAL':
+            default: // There shouldn't be any other options...
+                $case = 'NOMINATIVE';
+                break;
+            }
+        }
+        // Build up the formatted date, character at a time
+        preg_match_all('/%[^%]/', $format, $matches);
+        foreach ($matches[0] as $match) {
+            switch ($match) {
+            case '%d':
+                $format = str_replace($match, $this->formatDayZeros(), $format);
+                break;
+            case '%j':
+                $format = str_replace($match, $this->formatDay(), $format);
+                break;
+            case '%l':
+                $format = str_replace($match, $this->formatLongWeekday(), $format);
+                break;
+            case '%D':
+                $format = str_replace($match, $this->formatShortWeekday(), $format);
+                break;
+            case '%N':
+                $format = str_replace($match, $this->formatIsoWeekday(), $format);
+                break;
+            case '%w':
+                $format = str_replace($match, $this->formatNumericWeekday(), $format);
+                break;
+            case '%z':
+                $format = str_replace($match, $this->formatDayOfYear(), $format);
+                break;
+            case '%F':
+                $format = str_replace($match, $this->formatLongMonth($case), $format);
+                break;
+            case '%m':
+                $format = str_replace($match, $this->formatMonthZeros(), $format);
+                break;
+            case '%M':
+                $format = str_replace($match, $this->formatShortMonth(), $format);
+                break;
+            case '%n':
+                $format = str_replace($match, $this->formatMonth(), $format);
+                break;
+            case '%t':
+                $format = str_replace($match, $this->daysInMonth(), $format);
+                break;
+            case '%L':
+                $format = str_replace($match, (int) $this->isLeapYear(), $format);
+                break;
+            case '%Y':
+                $format = str_replace($match, $this->formatLongYear(), $format);
+                break;
+            case '%y':
+                $format = str_replace($match, $this->formatShortYear(), $format);
+                break;
+                // These 4 extensions are useful for re-formatting gedcom dates.
+            case '%@':
+                $format = str_replace($match, $this->calendar->gedcomCalendarEscape(), $format);
+                break;
+            case '%A':
+                $format = str_replace($match, $this->formatGedcomDay(), $format);
+                break;
+            case '%O':
+                $format = str_replace($match, $this->formatGedcomMonth(), $format);
+                break;
+            case '%E':
+                $format = str_replace($match, $this->formatGedcomYear(), $format);
+                break;
+            }
+        }
+
+        return $format;
+    }
+
+    /**
+     * Generate the %d format for a date.
+     *
+     * @return string
+     */
+    protected function formatDayZeros() {
+        if ($this->d > 9) {
+            return I18N::digits($this->d);
+        } else {
+            return I18N::digits('0' . $this->d);
+        }
+    }
+
+    /**
+     * Generate the %j format for a date.
+     *
+     * @return string
+     */
+    protected function formatDay() {
+        return I18N::digits($this->d);
+    }
+
+    /**
+     * Generate the %l format for a date.
+     *
+     * @return string
+     */
+    protected function formatLongWeekday() {
+        return $this->dayNames($this->minJD % $this->calendar->daysInWeek());
+    }
+
+    /**
+     * Generate the %D format for a date.
+     *
+     * @return string
+     */
+    protected function formatShortWeekday() {
+        return $this->dayNamesAbbreviated($this->minJD % $this->calendar->daysInWeek());
+    }
+
+    /**
+     * Generate the %N format for a date.
+     *
+     * @return string
+     */
+    protected function formatIsoWeekday() {
+        return I18N::digits($this->minJD % 7 + 1);
+    }
+
+    /**
+     * Generate the %w format for a date.
+     *
+     * @return string
+     */
+    protected function formatNumericWeekday() {
+        return I18N::digits(($this->minJD + 1) % $this->calendar->daysInWeek());
+    }
+
+    /**
+     * Generate the %z format for a date.
+     *
+     * @return string
+     */
+    protected function formatDayOfYear() {
+        return I18N::digits($this->minJD - $this->calendar->ymdToJd($this->y, 1, 1));
+    }
+
+    /**
+     * Generate the %n format for a date.
+     *
+     * @return string
+     */
+    protected function formatMonth() {
+        return I18N::digits($this->m);
+    }
+
+    /**
+     * Generate the %m format for a date.
+     *
+     * @return string
+     */
+    protected function formatMonthZeros() {
+        if ($this->m > 9) {
+            return I18N::digits($this->m);
+        } else {
+            return I18N::digits('0' . $this->m);
+        }
+    }
+
+    /**
+     * Generate the %F format for a date.
+     *
+     * @param string $case Which grammatical case shall we use
+     *
+     * @return string
+     */
+    protected function formatLongMonth($case = 'NOMINATIVE') {
+        switch ($case) {
+        case 'GENITIVE':
+            return $this->monthNameGenitiveCase($this->m, $this->isLeapYear());
+        case 'NOMINATIVE':
+            return $this->monthNameNominativeCase($this->m, $this->isLeapYear());
+        case 'LOCATIVE':
+            return $this->monthNameLocativeCase($this->m, $this->isLeapYear());
+        case 'INSTRUMENTAL':
+            return $this->monthNameInstrumentalCase($this->m, $this->isLeapYear());
+        default:
+            throw new \InvalidArgumentException($case);
+        }
+    }
+
+    /**
+     * Generate the %M format for a date.
+     *
+     * @return string
+     */
+    protected function formatShortMonth() {
+        return $this->monthNameAbbreviated($this->m, $this->isLeapYear());
+    }
+
+    /**
+     * Generate the %y format for a date.
+     *
+     * NOTE Short year is NOT a 2-digit year. It is for calendars such as hebrew
+     * which have a 3-digit form of 4-digit years.
+     *
+     * @return string
+     */
+    protected function formatShortYear() {
+        return $this->formatLongYear();
+    }
+
+    /**
+     * Generate the %A format for a date.
+     *
+     * @return string
+     */
+    protected function formatGedcomDay() {
+        if ($this->d == 0) {
+            return '';
+        } else {
+            return sprintf('%02d', $this->d);
+        }
+    }
+
+    /**
+     * Generate the %O format for a date.
+     *
+     * @return string
+     */
+    protected function formatGedcomMonth() {
+        // Our simple lookup table doesn't work correctly for Adar on leap years
+        if ($this->m == 7 && $this->calendar instanceof JewishCalendar && !$this->calendar->isLeapYear($this->y)) {
+            return 'ADR';
+        } else {
+            return array_search($this->m, static::$MONTH_ABBREV);
+        }
+    }
+
+    /**
+     * Generate the %E format for a date.
+     *
+     * @return string
+     */
+    protected function formatGedcomYear() {
+        if ($this->y == 0) {
+            return '';
+        } else {
+            return sprintf('%04d', $this->y);
+        }
+    }
+
+    /**
+     * Generate the %Y format for a date.
+     *
+     * @return string
+     */
+    protected function formatLongYear() {
+        return I18N::digits($this->y);
+    }
+
+    /**
+     * Which months follows this one? Calendars with leap-months should provide their own implementation.
+     *
+     * @return int[]
+     */
+    protected function nextMonth() {
+        return array($this->m === $this->calendar->monthsInYear() ? $this->nextYear($this->y) : $this->y, ($this->m % $this->calendar->monthsInYear()) + 1);
+    }
+
+    /**
+     * Convert a decimal number to roman numerals
+     *
+     * @param int $number
+     *
+     * @return string
+     */
+    protected function numberToRomanNumerals($number) {
+        if ($number < 1) {
+            // Cannot convert zero/negative numbers
+            return (string) $number;
+        }
+        $roman = '';
+        foreach (self::$roman_numerals as $key => $value) {
+            while ($number >= $key) {
+                $roman .= $value;
+                $number -= $key;
+            }
+        }
+
+        return $roman;
+    }
+
+    /**
+     * Convert a roman numeral to decimal
+     *
+     * @param string $roman
+     *
+     * @return int
+     */
+    protected function romanNumeralsToNumber($roman) {
+        $num = 0;
+        foreach (self::$roman_numerals as $key => $value) {
+            if (strpos($roman, $value) === 0) {
+                $num += $key;
+                $roman = substr($roman, strlen($value));
+            }
+        }
+
+        return $num;
+    }
+
+    /**
+     * Get today’s date in the current calendar.
+     *
+     * @return int[]
+     */
+    public function todayYmd() {
+        return $this->calendar->jdToYmd(unixtojd());
+    }
+
+    /**
+     * Convert to today’s date.
+     *
+     * @return CalendarDate
+     */
+    public function today() {
+        $tmp    = clone $this;
+        $ymd    = $tmp->todayYmd();
+        $tmp->y = $ymd[0];
+        $tmp->m = $ymd[1];
+        $tmp->d = $ymd[2];
+        $tmp->setJdFromYmd();
+
+        return $tmp;
+    }
+
+    /**
+     * Create a URL that links this date to the WT calendar
+     *
+     * @param string $date_format
+     *
+     * @return string
+     */
+    public function calendarUrl($date_format) {
+        if (strpbrk($date_format, 'dDj') && $this->d) {
+            // If the format includes a day, and the date also includes a day, then use the day view
+            $view = 'day';
+        } elseif (strpbrk($date_format, 'FMmn') && $this->m) {
+            // If the format includes a month, and the date also includes a month, then use the month view
+            $view = 'month';
+        } else {
+            // Use the year view
+            $view = 'year';
+        }
+
+        return
+            'calendar.php?cal=' . rawurlencode($this->calendar->gedcomCalendarEscape()) .
+            '&amp;year=' . $this->formatGedcomYear() .
+            '&amp;month=' . $this->formatGedcomMonth() .
+            '&amp;day=' . $this->formatGedcomDay() .
+            '&amp;view=' . $view;
+    }
 }