PhpSpreadsheet\Calculation\DateTime

Complexity

Total Complexity

289

Size/Duplication

Total Lines	1535
Duplicated Lines	14.79 %

Coupling/Cohesion

Components	2
Dependencies	3

Importance

Changes	1
Bugs	0	Features	0

26 Methods

Rating	Name	Duplication	Size	Complexity
A	isLeapYear()	0	4	3
C	dateDiff360()	0	23	11
B	getDateValue()	0	18	6
A	getTimeValue()	0	8	1
B	adjustDateByMonths()	0	25	4
A	DATETIMENOW()	0	20	4
A	DATENOW()	0	21	4
F	DATE()	8	66	24
F	TIME()	30	80	23
F	DATEVALUE()	8	108	34
D	TIMEVALUE()	8	37	10
D	DATEDIF()	17	93	20
B	DAYS360()	0	29	4
C	YEARFRAC()	0	71	28
C	NETWORKDAYS()	0	60	14
F	WORKDAY()	22	90	30
B	DAYOFMONTH()	0	19	5
C	DAYOFWEEK()	0	54	16
C	WEEKOFYEAR()	5	31	7
A	MONTHOFYEAR()	18	18	4
A	YEAR()	17	17	4
C	HOUROFDAY()	26	26	7
C	MINUTEOFHOUR()	26	26	7
C	SECONDOFMINUTE()	26	26	7
B	EDATE()	8	26	6
B	EOMONTH()	8	29	6

<?php

namespace PhpSpreadsheet\Calculation;

/**
 * Copyright (c) 2006 - 2016 PhpSpreadsheet
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * @category    PhpSpreadsheet
 * @copyright    Copyright (c) 2006 - 2016 PhpSpreadsheet (https://github.com/PHPOffice/PhpSpreadsheet)
 * @license        http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version        ##VERSION##, ##DATE##
 */
class DateTime
{
    /**
     * Identify if a year is a leap year or not
     *
     * @param    integer    $year    The year to test
     * @return    boolean            TRUE if the year is a leap year, otherwise FALSE
     */
    public static function isLeapYear($year)
    {
        return ((($year % 4) == 0) && (($year % 100) != 0) || (($year % 400) == 0));
    }


    /**
     * Return the number of days between two dates based on a 360 day calendar
     *
     * @param    integer    $startDay        Day of month of the start date
     * @param    integer    $startMonth        Month of the start date
     * @param    integer    $startYear        Year of the start date
     * @param    integer    $endDay            Day of month of the start date
     * @param    integer    $endMonth        Month of the start date
     * @param    integer    $endYear        Year of the start date
     * @param    boolean $methodUS        Whether to use the US method or the European method of calculation
     * @return    integer    Number of days between the start date and the end date
     */
    private static function dateDiff360($startDay, $startMonth, $startYear, $endDay, $endMonth, $endYear, $methodUS)
    {
        if ($startDay == 31) {
            --$startDay;
        } elseif ($methodUS && ($startMonth == 2 && ($startDay == 29 || ($startDay == 28 && !self::isLeapYear($startYear))))) {
            $startDay = 30;
        }
        if ($endDay == 31) {
            if ($methodUS && $startDay != 30) {
                $endDay = 1;
                if ($endMonth == 12) {
                    ++$endYear;
                    $endMonth = 1;
                } else {
                    ++$endMonth;
                }
            } else {
                $endDay = 30;
            }
        }

        return $endDay + $endMonth * 30 + $endYear * 360 - $startDay - $startMonth * 30 - $startYear * 360;
    }


    /**
     * getDateValue
     *
     * @param    string    $dateValue
     * @return    mixed    Excel date/time serial value, or string if error
     */
    public static function getDateValue($dateValue)
    {
        if (!is_numeric($dateValue)) {
            if ((is_string($dateValue)) &&
                (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_GNUMERIC)) {
                return Functions::VALUE();
            }
            if ((is_object($dateValue)) && ($dateValue instanceof \DateTime)) {
                $dateValue = \PhpSpreadsheet\Shared\Date::PHPToExcel($dateValue);
            } else {
                $saveReturnDateType = Functions::getReturnDateType();
                Functions::setReturnDateType(Functions::RETURNDATE_EXCEL);
                $dateValue = self::DATEVALUE($dateValue);
                Functions::setReturnDateType($saveReturnDateType);
            }
        }
        return $dateValue;
    }


    /**
     * getTimeValue
     *
     * @param    string    $timeValue
     * @return    mixed    Excel date/time serial value, or string if error
     */
    private static function getTimeValue($timeValue)
    {
        $saveReturnDateType = Functions::getReturnDateType();
        Functions::setReturnDateType(Functions::RETURNDATE_EXCEL);
        $timeValue = self::TIMEVALUE($timeValue);
        Functions::setReturnDateType($saveReturnDateType);
        return $timeValue;
    }


    private static function adjustDateByMonths($dateValue = 0, $adjustmentMonths = 0)
    {
        // Execute function
        $PHPDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
        $oMonth = (int) $PHPDateObject->format('m');
        $oYear = (int) $PHPDateObject->format('Y');

        $adjustmentMonthsString = (string) $adjustmentMonths;
        if ($adjustmentMonths > 0) {
            $adjustmentMonthsString = '+'.$adjustmentMonths;
        }
        if ($adjustmentMonths != 0) {
            $PHPDateObject->modify($adjustmentMonthsString.' months');
        }
        $nMonth = (int) $PHPDateObject->format('m');
        $nYear = (int) $PHPDateObject->format('Y');

        $monthDiff = ($nMonth - $oMonth) + (($nYear - $oYear) * 12);
        if ($monthDiff != $adjustmentMonths) {
            $adjustDays = (int) $PHPDateObject->format('d');
            $adjustDaysString = '-'.$adjustDays.' days';
            $PHPDateObject->modify($adjustDaysString);
        }
        return $PHPDateObject;
    }


    /**
     * DATETIMENOW
     *
     * Returns the current date and time.
     * The NOW function is useful when you need to display the current date and time on a worksheet or
     * calculate a value based on the current date and time, and have that value updated each time you
     * open the worksheet.
     *
     * NOTE: When used in a Cell Formula, MS Excel changes the cell format so that it matches the date
     * and time format of your regional settings. PhpSpreadsheet does not change cell formatting in this way.
     *
     * Excel Function:
     *        NOW()
     *
     * @access    public
     * @category Date/Time Functions
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function DATETIMENOW()
    {
        $saveTimeZone = date_default_timezone_get();
        date_default_timezone_set('UTC');
        $retValue = false;
        switch (Functions::getReturnDateType()) {
            case Functions::RETURNDATE_EXCEL:
                $retValue = (float) \PhpSpreadsheet\Shared\Date::PHPToExcel(time());
                break;
            case Functions::RETURNDATE_PHP_NUMERIC:
                $retValue = (integer) time();
                break;
            case Functions::RETURNDATE_PHP_OBJECT:
                $retValue = new \DateTime();
                break;
        }
        date_default_timezone_set($saveTimeZone);

        return $retValue;
    }


    /**
     * DATENOW
     *
     * Returns the current date.
     * The NOW function is useful when you need to display the current date and time on a worksheet or
     * calculate a value based on the current date and time, and have that value updated each time you
     * open the worksheet.
     *
     * NOTE: When used in a Cell Formula, MS Excel changes the cell format so that it matches the date
     * and time format of your regional settings. PhpSpreadsheet does not change cell formatting in this way.
     *
     * Excel Function:
     *        TODAY()
     *
     * @access    public
     * @category Date/Time Functions
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function DATENOW()
    {
        $saveTimeZone = date_default_timezone_get();
        date_default_timezone_set('UTC');
        $retValue = false;
        $excelDateTime = floor(\PhpSpreadsheet\Shared\Date::PHPToExcel(time()));
        switch (Functions::getReturnDateType()) {
            case Functions::RETURNDATE_EXCEL:
                $retValue = (float) $excelDateTime;
                break;
            case Functions::RETURNDATE_PHP_NUMERIC:
                $retValue = (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateTime);
                break;
            case Functions::RETURNDATE_PHP_OBJECT:
                $retValue = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($excelDateTime);
                break;
        }
        date_default_timezone_set($saveTimeZone);

        return $retValue;
    }


    /**
     * DATE
     *
     * The DATE function returns a value that represents a particular date.
     *
     * NOTE: When used in a Cell Formula, MS Excel changes the cell format so that it matches the date
     * format of your regional settings. PhpSpreadsheet does not change cell formatting in this way.
     *
     * Excel Function:
     *        DATE(year,month,day)
     *
     * PhpSpreadsheet is a lot more forgiving than MS Excel when passing non numeric values to this function.
     * A Month name or abbreviation (English only at this point) such as 'January' or 'Jan' will still be accepted,
     *     as will a day value with a suffix (e.g. '21st' rather than simply 21); again only English language.
     *
     * @access    public
     * @category Date/Time Functions
     * @param    integer        $year    The value of the year argument can include one to four digits.
     *                                Excel interprets the year argument according to the configured
     *                                date system: 1900 or 1904.
     *                                If year is between 0 (zero) and 1899 (inclusive), Excel adds that
     *                                value to 1900 to calculate the year. For example, DATE(108,1,2)
     *                                returns January 2, 2008 (1900+108).
     *                                If year is between 1900 and 9999 (inclusive), Excel uses that
     *                                value as the year. For example, DATE(2008,1,2) returns January 2,
     *                                2008.
     *                                If year is less than 0 or is 10000 or greater, Excel returns the
     *                                #NUM! error value.
     * @param    integer        $month    A positive or negative integer representing the month of the year
     *                                from 1 to 12 (January to December).
     *                                If month is greater than 12, month adds that number of months to
     *                                the first month in the year specified. For example, DATE(2008,14,2)
     *                                returns the serial number representing February 2, 2009.
     *                                If month is less than 1, month subtracts the magnitude of that
     *                                number of months, plus 1, from the first month in the year
     *                                specified. For example, DATE(2008,-3,2) returns the serial number
     *                                representing September 2, 2007.
     * @param    integer        $day    A positive or negative integer representing the day of the month
     *                                from 1 to 31.
     *                                If day is greater than the number of days in the month specified,
     *                                day adds that number of days to the first day in the month. For
     *                                example, DATE(2008,1,35) returns the serial number representing
     *                                February 4, 2008.
     *                                If day is less than 1, day subtracts the magnitude that number of
     *                                days, plus one, from the first day of the month specified. For
     *                                example, DATE(2008,1,-15) returns the serial number representing
     *                                December 16, 2007.
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function DATE($year = 0, $month = 1, $day = 1)
    {
        $year  = Functions::flattenSingleValue($year);
        $month = Functions::flattenSingleValue($month);
        $day   = Functions::flattenSingleValue($day);

        if (($month !== null) && (!is_numeric($month))) {
            $month = \PhpSpreadsheet\Shared\Date::monthStringToNumber($month);

It seems like $month defined by \PhpSpreadsheet\Shared\Date::monthStringToNumber($month) on line 287 can also be of type boolean or object; however, PhpSpreadsheet\Shared\Date::monthStringToNumber() does only seem to accept string, maybe add an additional type check?

        }

        if (($day !== null) && (!is_numeric($day))) {
            $day = \PhpSpreadsheet\Shared\Date::dayStringToNumber($day);

It seems like $day defined by \PhpSpreadsheet\Shared\Date::dayStringToNumber($day) on line 291 can also be of type boolean or object; however, PhpSpreadsheet\Shared\Date::dayStringToNumber() does only seem to accept string, maybe add an additional type check?

        }

        $year = ($year !== null) ? \PhpSpreadsheet\Shared\StringHelper::testStringAsNumeric($year) : 0;
        $month = ($month !== null) ? \PhpSpreadsheet\Shared\StringHelper::testStringAsNumeric($month) : 0;
        $day = ($day !== null) ? \PhpSpreadsheet\Shared\StringHelper::testStringAsNumeric($day) : 0;
        if ((!is_numeric($year)) ||
            (!is_numeric($month)) ||
            (!is_numeric($day))) {
            return Functions::VALUE();
        }
        $year    = (integer) $year;
        $month    = (integer) $month;
        $day    = (integer) $day;

        $baseYear = \PhpSpreadsheet\Shared\Date::getExcelCalendar();
        // Validate parameters
        if ($year < ($baseYear-1900)) {
            return Functions::NAN();
        }
        if ((($baseYear-1900) != 0) && ($year < $baseYear) && ($year >= 1900)) {
            return Functions::NAN();
        }

        if (($year < $baseYear) && ($year >= ($baseYear-1900))) {
            $year += 1900;
        }

        if ($month < 1) {
            //    Handle year/month adjustment if month < 1
            --$month;
            $year += ceil($month / 12) - 1;
            $month = 13 - abs($month % 12);
        } elseif ($month > 12) {
            //    Handle year/month adjustment if month > 12
            $year += floor($month / 12);
            $month = ($month % 12);
        }

        // Re-validate the year parameter after adjustments
        if (($year < $baseYear) || ($year >= 10000)) {
            return Functions::NAN();
        }

        // Execute function
        $excelDateValue = \PhpSpreadsheet\Shared\Date::formattedPHPToExcel($year, $month, $day);
        switch (Functions::getReturnDateType()) {

This code seems to be duplicated across your project.

            case Functions::RETURNDATE_EXCEL:
                return (float) $excelDateValue;
            case Functions::RETURNDATE_PHP_NUMERIC:
                return (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateValue);
            case Functions::RETURNDATE_PHP_OBJECT:
                return \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($excelDateValue);
        }
    }


    /**
     * TIME
     *
     * The TIME function returns a value that represents a particular time.
     *
     * NOTE: When used in a Cell Formula, MS Excel changes the cell format so that it matches the time
     * format of your regional settings. PhpSpreadsheet does not change cell formatting in this way.
     *
     * Excel Function:
     *        TIME(hour,minute,second)
     *
     * @access    public
     * @category Date/Time Functions
     * @param    integer        $hour        A number from 0 (zero) to 32767 representing the hour.
     *                                    Any value greater than 23 will be divided by 24 and the remainder
     *                                    will be treated as the hour value. For example, TIME(27,0,0) =
     *                                    TIME(3,0,0) = .125 or 3:00 AM.
     * @param    integer        $minute        A number from 0 to 32767 representing the minute.
     *                                    Any value greater than 59 will be converted to hours and minutes.
     *                                    For example, TIME(0,750,0) = TIME(12,30,0) = .520833 or 12:30 PM.
     * @param    integer        $second        A number from 0 to 32767 representing the second.
     *                                    Any value greater than 59 will be converted to hours, minutes,
     *                                    and seconds. For example, TIME(0,0,2000) = TIME(0,33,22) = .023148
     *                                    or 12:33:20 AM
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function TIME($hour = 0, $minute = 0, $second = 0)
    {
        $hour = Functions::flattenSingleValue($hour);
        $minute = Functions::flattenSingleValue($minute);
        $second = Functions::flattenSingleValue($second);

        if ($hour == '') {
            $hour = 0;
        }
        if ($minute == '') {
            $minute = 0;
        }
        if ($second == '') {
            $second = 0;
        }

        if ((!is_numeric($hour)) || (!is_numeric($minute)) || (!is_numeric($second))) {
            return Functions::VALUE();
        }
        $hour = (integer) $hour;
        $minute = (integer) $minute;
        $second = (integer) $second;

        if ($second < 0) {

This code seems to be duplicated across your project.

            $minute += floor($second / 60);
            $second = 60 - abs($second % 60);
            if ($second == 60) {
                $second = 0;
            }
        } elseif ($second >= 60) {
            $minute += floor($second / 60);
            $second = $second % 60;
        }
        if ($minute < 0) {

This code seems to be duplicated across your project.

            $hour += floor($minute / 60);
            $minute = 60 - abs($minute % 60);
            if ($minute == 60) {
                $minute = 0;
            }
        } elseif ($minute >= 60) {
            $hour += floor($minute / 60);
            $minute = $minute % 60;
        }

        if ($hour > 23) {
            $hour = $hour % 24;
        } elseif ($hour < 0) {
            return Functions::NAN();
        }

        // Execute function
        switch (Functions::getReturnDateType()) {
            case Functions::RETURNDATE_EXCEL:
                $date = 0;
                $calendar = \PhpSpreadsheet\Shared\Date::getExcelCalendar();
                if ($calendar != \PhpSpreadsheet\Shared\Date::CALENDAR_WINDOWS_1900) {
                    $date = 1;
                }
                return (float) \PhpSpreadsheet\Shared\Date::formattedPHPToExcel($calendar, 1, $date, $hour, $minute, $second);
            case Functions::RETURNDATE_PHP_NUMERIC:
                return (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp(\PhpSpreadsheet\Shared\Date::formattedPHPToExcel(1970, 1, 1, $hour, $minute, $second));    // -2147468400; //    -2147472000 + 3600
            case Functions::RETURNDATE_PHP_OBJECT:
                $dayAdjust = 0;
                if ($hour < 0) {

This code seems to be duplicated across your project.

                    $dayAdjust = floor($hour / 24);
                    $hour = 24 - abs($hour % 24);
                    if ($hour == 24) {
                        $hour = 0;
                    }
                } elseif ($hour >= 24) {
                    $dayAdjust = floor($hour / 24);
                    $hour = $hour % 24;
                }
                $phpDateObject = new \DateTime('1900-01-01 '.$hour.':'.$minute.':'.$second);
                if ($dayAdjust != 0) {
                    $phpDateObject->modify($dayAdjust.' days');
                }
                return $phpDateObject;
        }
    }


    /**
     * DATEVALUE
     *
     * Returns a value that represents a particular date.
     * Use DATEVALUE to convert a date represented by a text string to an Excel or PHP date/time stamp
     * value.
     *
     * NOTE: When used in a Cell Formula, MS Excel changes the cell format so that it matches the date
     * format of your regional settings. PhpSpreadsheet does not change cell formatting in this way.
     *
     * Excel Function:
     *        DATEVALUE(dateValue)
     *
     * @access    public
     * @category Date/Time Functions
     * @param    string    $dateValue        Text that represents a date in a Microsoft Excel date format.
     *                                    For example, "1/30/2008" or "30-Jan-2008" are text strings within
     *                                    quotation marks that represent dates. Using the default date
     *                                    system in Excel for Windows, date_text must represent a date from
     *                                    January 1, 1900, to December 31, 9999. Using the default date
     *                                    system in Excel for the Macintosh, date_text must represent a date
     *                                    from January 1, 1904, to December 31, 9999. DATEVALUE returns the
     *                                    #VALUE! error value if date_text is out of this range.
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function DATEVALUE($dateValue = 1)
    {
        $dateValueOrig= $dateValue;

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

        $dateValue = trim(Functions::flattenSingleValue($dateValue), '"');
        //    Strip any ordinals because they're allowed in Excel (English only)
        $dateValue = preg_replace('/(\d)(st|nd|rd|th)([ -\/])/Ui', '$1$3', $dateValue);
        //    Convert separators (/ . or space) to hyphens (should also handle dot used for ordinals in some countries, e.g. Denmark, Germany)
        $dateValue    = str_replace(array('/', '.', '-', '  '), array(' ', ' ', ' ', ' '), $dateValue);

        $yearFound = false;
        $t1 = explode(' ', $dateValue);
        foreach ($t1 as &$t) {
            if ((is_numeric($t)) && ($t > 31)) {
                if ($yearFound) {
                    return Functions::VALUE();
                } else {
                    if ($t < 100) {
                        $t += 1900;
                    }
                    $yearFound = true;
                }
            }
        }
        if ((count($t1) == 1) && (strpos($t, ':') != false)) {

The variable $t does not seem to be defined for all execution paths leading up to this point.

It seems like you are loosely comparing strpos($t, ':') of type integer to the boolean false. If you are specifically checking for non-zero, consider using something more explicit like > 0 or !== 0 instead.

            //    We've been fed a time value without any date
            return 0.0;
        } elseif (count($t1) == 2) {
            //    We only have two parts of the date: either day/month or month/year
            if ($yearFound) {
                array_unshift($t1, 1);
            } else {
                if ($t1[1] > 29) {
                    $t1[1] += 1900;
                    array_unshift($t1, 1);
                } else {
                    array_push($t1, date('Y'));
                }
            }
        }
        unset($t);
        $dateValue = implode(' ', $t1);

        $PHPDateArray = date_parse($dateValue);
        if (($PHPDateArray === false) || ($PHPDateArray['error_count'] > 0)) {
            $testVal1 = strtok($dateValue, '- ');
            if ($testVal1 !== false) {
                $testVal2 = strtok('- ');
                if ($testVal2 !== false) {
                    $testVal3 = strtok('- ');
                    if ($testVal3 === false) {
                        $testVal3 = strftime('%Y');
                    }
                } else {
                    return Functions::VALUE();
                }
            } else {
                return Functions::VALUE();
            }
            if ($testVal1 < 31 && $testVal2 < 12 && $testVal3 < 12 && strlen($testVal3) == 2) {
                $testVal3 += 2000;
            }
            $PHPDateArray = date_parse($testVal1.'-'.$testVal2.'-'.$testVal3);
            if (($PHPDateArray === false) || ($PHPDateArray['error_count'] > 0)) {
                $PHPDateArray = date_parse($testVal2.'-'.$testVal1.'-'.$testVal3);
                if (($PHPDateArray === false) || ($PHPDateArray['error_count'] > 0)) {
                    return Functions::VALUE();
                }
            }
        }

        if (($PHPDateArray !== false) && ($PHPDateArray['error_count'] == 0)) {
            // Execute function
            if ($PHPDateArray['year'] == '') {
                $PHPDateArray['year'] = strftime('%Y');
            }
            if ($PHPDateArray['year'] < 1900) {
                return Functions::VALUE();
            }
            if ($PHPDateArray['month'] == '') {
                $PHPDateArray['month'] = strftime('%m');
            }
            if ($PHPDateArray['day'] == '') {
                $PHPDateArray['day'] = strftime('%d');
            }
            if (!checkdate($PHPDateArray['month'], $PHPDateArray['day'], $PHPDateArray['year'])) {
                return Functions::VALUE();
            }
            $excelDateValue = floor(
                \PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
                    $PHPDateArray['year'],
                    $PHPDateArray['month'],
                    $PHPDateArray['day'],
                    $PHPDateArray['hour'],
                    $PHPDateArray['minute'],
                    $PHPDateArray['second']
                )
            );
            switch (Functions::getReturnDateType()) {

This code seems to be duplicated across your project.

                case Functions::RETURNDATE_EXCEL:
                    return (float) $excelDateValue;
                case Functions::RETURNDATE_PHP_NUMERIC:
                    return (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateValue);
                case Functions::RETURNDATE_PHP_OBJECT:
                    return new \DateTime($PHPDateArray['year'].'-'.$PHPDateArray['month'].'-'.$PHPDateArray['day'].' 00:00:00');
            }
        }
        return Functions::VALUE();
    }


    /**
     * TIMEVALUE
     *
     * Returns a value that represents a particular time.
     * Use TIMEVALUE to convert a time represented by a text string to an Excel or PHP date/time stamp
     * value.
     *
     * NOTE: When used in a Cell Formula, MS Excel changes the cell format so that it matches the time
     * format of your regional settings. PhpSpreadsheet does not change cell formatting in this way.
     *
     * Excel Function:
     *        TIMEVALUE(timeValue)
     *
     * @access    public
     * @category Date/Time Functions
     * @param    string    $timeValue        A text string that represents a time in any one of the Microsoft
     *                                    Excel time formats; for example, "6:45 PM" and "18:45" text strings
     *                                    within quotation marks that represent time.
     *                                    Date information in time_text is ignored.
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function TIMEVALUE($timeValue)
    {
        $timeValue = trim(Functions::flattenSingleValue($timeValue), '"');
        $timeValue = str_replace(array('/', '.'), array('-', '-'), $timeValue);

        $arraySplit = preg_split('/[\/:\-\s]/', $timeValue);
        if ((count($arraySplit) == 2 ||count($arraySplit) == 3) && $arraySplit[0] > 24) {
            $arraySplit[0] = ($arraySplit[0] % 24);
            $timeValue = implode(':', $arraySplit);
        }

        $PHPDateArray = date_parse($timeValue);
        if (($PHPDateArray !== false) && ($PHPDateArray['error_count'] == 0)) {
            if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_OPENOFFICE) {
                $excelDateValue = \PhpSpreadsheet\Shared\Date::formattedPHPToExcel(
                    $PHPDateArray['year'],
                    $PHPDateArray['month'],
                    $PHPDateArray['day'],
                    $PHPDateArray['hour'],
                    $PHPDateArray['minute'],
                    $PHPDateArray['second']
                );
            } else {
                $excelDateValue = \PhpSpreadsheet\Shared\Date::formattedPHPToExcel(1900, 1, 1, $PHPDateArray['hour'], $PHPDateArray['minute'], $PHPDateArray['second']) - 1;
            }

            switch (Functions::getReturnDateType()) {

This code seems to be duplicated across your project.

                case Functions::RETURNDATE_EXCEL:
                    return (float) $excelDateValue;
                case Functions::RETURNDATE_PHP_NUMERIC:
                    return (integer) $phpDateValue = \PhpSpreadsheet\Shared\Date::excelToTimestamp($excelDateValue+25569) - 3600;
                case Functions::RETURNDATE_PHP_OBJECT:
                    return new \DateTime('1900-01-01 '.$PHPDateArray['hour'].':'.$PHPDateArray['minute'].':'.$PHPDateArray['second']);
            }
        }
        return Functions::VALUE();
    }


    /**
     * DATEDIF
     *
     * @param    mixed    $startDate        Excel date serial value, PHP date/time stamp, PHP DateTime object
     *                                    or a standard date string
     * @param    mixed    $endDate        Excel date serial value, PHP date/time stamp, PHP DateTime object
     *                                    or a standard date string
     * @param    string    $unit
     * @return    integer    Interval between the dates
     */
    public static function DATEDIF($startDate = 0, $endDate = 0, $unit = 'D')
    {
        $startDate = Functions::flattenSingleValue($startDate);
        $endDate   = Functions::flattenSingleValue($endDate);
        $unit      = strtoupper(Functions::flattenSingleValue($unit));

        if (is_string($startDate = self::getDateValue($startDate))) {
            return Functions::VALUE();
        }
        if (is_string($endDate = self::getDateValue($endDate))) {
            return Functions::VALUE();
        }

        // Validate parameters
        if ($startDate >= $endDate) {
            return Functions::NAN();
        }

        // Execute function
        $difference = $endDate - $startDate;

        $PHPStartDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($startDate);
        $startDays = $PHPStartDateObject->format('j');
        $startMonths = $PHPStartDateObject->format('n');
        $startYears = $PHPStartDateObject->format('Y');

        $PHPEndDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($endDate);
        $endDays = $PHPEndDateObject->format('j');
        $endMonths = $PHPEndDateObject->format('n');
        $endYears = $PHPEndDateObject->format('Y');

        $retVal = Functions::NAN();

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

        switch ($unit) {
            case 'D':
                $retVal = intval($difference);
                break;
            case 'M':

This code seems to be duplicated across your project.

                $retVal = intval($endMonths - $startMonths) + (intval($endYears - $startYears) * 12);
                //    We're only interested in full months
                if ($endDays < $startDays) {
                    --$retVal;
                }
                break;
            case 'Y':
                $retVal = intval($endYears - $startYears);
                //    We're only interested in full months
                if ($endMonths < $startMonths) {
                    --$retVal;
                } elseif (($endMonths == $startMonths) && ($endDays < $startDays)) {
                    // Remove start month
                    --$retVal;
                    // Remove end month
                    --$retVal;
                }
                break;
            case 'MD':
                if ($endDays < $startDays) {
                    $retVal = $endDays;
                    $PHPEndDateObject->modify('-'.$endDays.' days');
                    $adjustDays = $PHPEndDateObject->format('j');
                    $retVal += ($adjustDays - $startDays);
                } else {
                    $retVal = $endDays - $startDays;
                }
                break;
            case 'YM':

This code seems to be duplicated across your project.

                $retVal = intval($endMonths - $startMonths);
                if ($retVal < 0) {
                    $retVal += 12;
                }
                //    We're only interested in full months
                if ($endDays < $startDays) {
                    --$retVal;
                }
                break;
            case 'YD':
                $retVal = intval($difference);
                if ($endYears > $startYears) {
                    while ($endYears > $startYears) {
                        $PHPEndDateObject->modify('-1 year');
                        $endYears = $PHPEndDateObject->format('Y');
                    }
                    $retVal = $PHPEndDateObject->format('z') - $PHPStartDateObject->format('z');
                    if ($retVal < 0) {
                        $retVal += 365;
                    }
                }
                break;
            default:
                $retVal = Functions::VALUE();
        }
        return $retVal;
    }


    /**
     * DAYS360
     *
     * Returns the number of days between two dates based on a 360-day year (twelve 30-day months),
     * which is used in some accounting calculations. Use this function to help compute payments if
     * your accounting system is based on twelve 30-day months.
     *
     * Excel Function:
     *        DAYS360(startDate,endDate[,method])
     *
     * @access    public
     * @category Date/Time Functions
     * @param    mixed        $startDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                        PHP DateTime object, or a standard date string
     * @param    mixed        $endDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                        PHP DateTime object, or a standard date string
     * @param    boolean        $method            US or European Method
     *                                        FALSE or omitted: U.S. (NASD) method. If the starting date is
     *                                        the last day of a month, it becomes equal to the 30th of the
     *                                        same month. If the ending date is the last day of a month and
     *                                        the starting date is earlier than the 30th of a month, the
     *                                        ending date becomes equal to the 1st of the next month;
     *                                        otherwise the ending date becomes equal to the 30th of the
     *                                        same month.
     *                                        TRUE: European method. Starting dates and ending dates that
     *                                        occur on the 31st of a month become equal to the 30th of the
     *                                        same month.
     * @return    integer        Number of days between start date and end date
     */
    public static function DAYS360($startDate = 0, $endDate = 0, $method = false)
    {
        $startDate    = Functions::flattenSingleValue($startDate);
        $endDate    = Functions::flattenSingleValue($endDate);

        if (is_string($startDate = self::getDateValue($startDate))) {
            return Functions::VALUE();
        }
        if (is_string($endDate = self::getDateValue($endDate))) {
            return Functions::VALUE();
        }

        if (!is_bool($method)) {
            return Functions::VALUE();
        }

        // Execute function
        $PHPStartDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($startDate);
        $startDay = $PHPStartDateObject->format('j');
        $startMonth = $PHPStartDateObject->format('n');
        $startYear = $PHPStartDateObject->format('Y');

        $PHPEndDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($endDate);
        $endDay = $PHPEndDateObject->format('j');
        $endMonth = $PHPEndDateObject->format('n');
        $endYear = $PHPEndDateObject->format('Y');

        return self::dateDiff360($startDay, $startMonth, $startYear, $endDay, $endMonth, $endYear, !$method);
    }


    /**
     * YEARFRAC
     *
     * Calculates the fraction of the year represented by the number of whole days between two dates
     * (the start_date and the end_date).
     * Use the YEARFRAC worksheet function to identify the proportion of a whole year's benefits or
     * obligations to assign to a specific term.
     *
     * Excel Function:
     *        YEARFRAC(startDate,endDate[,method])
     *
     * @access    public
     * @category Date/Time Functions
     * @param    mixed    $startDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @param    mixed    $endDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @param    integer    $method            Method used for the calculation
     *                                        0 or omitted    US (NASD) 30/360
     *                                        1                Actual/actual
     *                                        2                Actual/360
     *                                        3                Actual/365
     *                                        4                European 30/360
     * @return    float    fraction of the year
     */
    public static function YEARFRAC($startDate = 0, $endDate = 0, $method = 0)
    {
        $startDate    = Functions::flattenSingleValue($startDate);
        $endDate    = Functions::flattenSingleValue($endDate);
        $method        = Functions::flattenSingleValue($method);

        if (is_string($startDate = self::getDateValue($startDate))) {
            return Functions::VALUE();
        }
        if (is_string($endDate = self::getDateValue($endDate))) {
            return Functions::VALUE();
        }

        if (((is_numeric($method)) && (!is_string($method))) || ($method == '')) {
            switch ($method) {
                case 0:
                    return self::DAYS360($startDate, $endDate) / 360;
                case 1:
                    $days = self::DATEDIF($startDate, $endDate);
                    $startYear = self::YEAR($startDate);
                    $endYear = self::YEAR($endDate);
                    $years = $endYear - $startYear + 1;
                    $leapDays = 0;
                    if ($years == 1) {
                        if (self::isLeapYear($endYear)) {
                            $startMonth = self::MONTHOFYEAR($startDate);
                            $endMonth = self::MONTHOFYEAR($endDate);
                            $endDay = self::DAYOFMONTH($endDate);
                            if (($startMonth < 3) ||
                                (($endMonth * 100 + $endDay) >= (2 * 100 + 29))) {
                                 $leapDays += 1;
                            }
                        }
                    } else {
                        for ($year = $startYear; $year <= $endYear; ++$year) {
                            if ($year == $startYear) {
                                $startMonth = self::MONTHOFYEAR($startDate);
                                $startDay = self::DAYOFMONTH($startDate);

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

                                if ($startMonth < 3) {
                                    $leapDays += (self::isLeapYear($year)) ? 1 : 0;
                                }
                            } elseif ($year == $endYear) {
                                $endMonth = self::MONTHOFYEAR($endDate);
                                $endDay = self::DAYOFMONTH($endDate);
                                if (($endMonth * 100 + $endDay) >= (2 * 100 + 29)) {
                                    $leapDays += (self::isLeapYear($year)) ? 1 : 0;
                                }
                            } else {
                                $leapDays += (self::isLeapYear($year)) ? 1 : 0;
                            }
                        }
                        if ($years == 2) {
                            if (($leapDays == 0) && (self::isLeapYear($startYear)) && ($days > 365)) {
                                $leapDays = 1;
                            } elseif ($days < 366) {
                                $years = 1;
                            }
                        }
                        $leapDays /= $years;
                    }
                    return $days / (365 + $leapDays);
                case 2:
                    return self::DATEDIF($startDate, $endDate) / 360;
                case 3:
                    return self::DATEDIF($startDate, $endDate) / 365;
                case 4:
                    return self::DAYS360($startDate, $endDate, true) / 360;
            }
        }
        return Functions::VALUE();
    }


    /**
     * NETWORKDAYS
     *
     * Returns the number of whole working days between start_date and end_date. Working days
     * exclude weekends and any dates identified in holidays.
     * Use NETWORKDAYS to calculate employee benefits that accrue based on the number of days
     * worked during a specific term.
     *
     * Excel Function:
     *        NETWORKDAYS(startDate,endDate[,holidays[,holiday[,...]]])
     *
     * @access    public
     * @category Date/Time Functions
     * @param    mixed            $startDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                            PHP DateTime object, or a standard date string
     * @param    mixed            $endDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                            PHP DateTime object, or a standard date string
     * @param    mixed            $holidays,...    Optional series of Excel date serial value (float), PHP date

There is no parameter named $holidays,.... Was it maybe removed?

     *                                            timestamp (integer), PHP DateTime object, or a standard date
     *                                            strings that will be excluded from the working calendar, such
     *                                            as state and federal holidays and floating holidays.
     * @return    integer            Interval between the dates
     */
    public static function NETWORKDAYS($startDate, $endDate)
    {
        //    Retrieve the mandatory start and end date that are referenced in the function definition
        $startDate    = Functions::flattenSingleValue($startDate);
        $endDate    = Functions::flattenSingleValue($endDate);
        //    Flush the mandatory start and end date that are referenced in the function definition, and get the optional days
        $dateArgs = Functions::flattenArray(func_get_args());
        array_shift($dateArgs);
        array_shift($dateArgs);

        //    Validate the start and end dates
        if (is_string($startDate = $sDate = self::getDateValue($startDate))) {
            return Functions::VALUE();
        }
        $startDate = (float) floor($startDate);
        if (is_string($endDate = $eDate = self::getDateValue($endDate))) {
            return Functions::VALUE();
        }
        $endDate = (float) floor($endDate);

        if ($sDate > $eDate) {
            $startDate = $eDate;
            $endDate = $sDate;
        }

        // Execute function
        $startDoW = 6 - self::DAYOFWEEK($startDate, 2);
        if ($startDoW < 0) {
            $startDoW = 0;
        }
        $endDoW = self::DAYOFWEEK($endDate, 2);
        if ($endDoW >= 6) {
            $endDoW = 0;
        }

        $wholeWeekDays = floor(($endDate - $startDate) / 7) * 5;
        $partWeekDays = $endDoW + $startDoW;
        if ($partWeekDays > 5) {
            $partWeekDays -= 5;
        }

        //    Test any extra holiday parameters
        $holidayCountedArray = array();
        foreach ($dateArgs as $holidayDate) {
            if (is_string($holidayDate = self::getDateValue($holidayDate))) {
                return Functions::VALUE();
            }
            if (($holidayDate >= $startDate) && ($holidayDate <= $endDate)) {
                if ((self::DAYOFWEEK($holidayDate, 2) < 6) && (!in_array($holidayDate, $holidayCountedArray))) {
                    --$partWeekDays;
                    $holidayCountedArray[] = $holidayDate;
                }
            }
        }

        if ($sDate > $eDate) {
            return 0 - ($wholeWeekDays + $partWeekDays);
        }
        return $wholeWeekDays + $partWeekDays;
    }


    /**
     * WORKDAY
     *
     * Returns the date that is the indicated number of working days before or after a date (the
     * starting date). Working days exclude weekends and any dates identified as holidays.
     * Use WORKDAY to exclude weekends or holidays when you calculate invoice due dates, expected
     * delivery times, or the number of days of work performed.
     *
     * Excel Function:
     *        WORKDAY(startDate,endDays[,holidays[,holiday[,...]]])
     *
     * @access    public
     * @category Date/Time Functions
     * @param    mixed        $startDate        Excel date serial value (float), PHP date timestamp (integer),
     *                                        PHP DateTime object, or a standard date string
     * @param    integer        $endDays        The number of nonweekend and nonholiday days before or after
     *                                        startDate. A positive value for days yields a future date; a
     *                                        negative value yields a past date.
     * @param    mixed        $holidays,...    Optional series of Excel date serial value (float), PHP date

There is no parameter named $holidays,.... Was it maybe removed?

     *                                        timestamp (integer), PHP DateTime object, or a standard date
     *                                        strings that will be excluded from the working calendar, such
     *                                        as state and federal holidays and floating holidays.
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function WORKDAY($startDate, $endDays)
    {
        //    Retrieve the mandatory start date and days that are referenced in the function definition
        $startDate    = Functions::flattenSingleValue($startDate);
        $endDays    = Functions::flattenSingleValue($endDays);
        //    Flush the mandatory start date and days that are referenced in the function definition, and get the optional days
        $dateArgs = Functions::flattenArray(func_get_args());
        array_shift($dateArgs);
        array_shift($dateArgs);

        if ((is_string($startDate = self::getDateValue($startDate))) || (!is_numeric($endDays))) {
            return Functions::VALUE();
        }
        $startDate = (float) floor($startDate);
        $endDays = (int) floor($endDays);
        //    If endDays is 0, we always return startDate
        if ($endDays == 0) {
            return $startDate;
        }

        $decrementing = ($endDays < 0) ? true : false;

        //    Adjust the start date if it falls over a weekend

        $startDoW = self::DAYOFWEEK($startDate, 3);
        if (self::DAYOFWEEK($startDate, 3) >= 5) {
            $startDate += ($decrementing) ? -$startDoW + 4: 7 - $startDoW;
            ($decrementing) ? $endDays++ : $endDays--;
        }

        //    Add endDays
        $endDate = (float) $startDate + (intval($endDays / 5) * 7) + ($endDays % 5);

        //    Adjust the calculated end date if it falls over a weekend
        $endDoW = self::DAYOFWEEK($endDate, 3);
        if ($endDoW >= 5) {
            $endDate += ($decrementing) ? -$endDoW + 4: 7 - $endDoW;
        }

        //    Test any extra holiday parameters
        if (!empty($dateArgs)) {
            $holidayCountedArray = $holidayDates = array();
            foreach ($dateArgs as $holidayDate) {
                if (($holidayDate !== null) && (trim($holidayDate) > '')) {
                    if (is_string($holidayDate = self::getDateValue($holidayDate))) {
                        return Functions::VALUE();
                    }
                    if (self::DAYOFWEEK($holidayDate, 3) < 5) {
                        $holidayDates[] = $holidayDate;
                    }
                }
            }
            if ($decrementing) {
                rsort($holidayDates, SORT_NUMERIC);
            } else {
                sort($holidayDates, SORT_NUMERIC);
            }
            foreach ($holidayDates as $holidayDate) {
                if ($decrementing) {
                    if (($holidayDate <= $startDate) && ($holidayDate >= $endDate)) {

This code seems to be duplicated across your project.

                        if (!in_array($holidayDate, $holidayCountedArray)) {
                            --$endDate;
                            $holidayCountedArray[] = $holidayDate;
                        }
                    }
                } else {

This code seems to be duplicated across your project.

                    if (($holidayDate >= $startDate) && ($holidayDate <= $endDate)) {
                        if (!in_array($holidayDate, $holidayCountedArray)) {
                            ++$endDate;
                            $holidayCountedArray[] = $holidayDate;
                        }
                    }
                }
                //    Adjust the calculated end date if it falls over a weekend
                $endDoW = self::DAYOFWEEK($endDate, 3);
                if ($endDoW >= 5) {
                    $endDate += ($decrementing) ? -$endDoW + 4 : 7 - $endDoW;
                }
            }
        }

        switch (Functions::getReturnDateType()) {

This code seems to be duplicated across your project.

            case Functions::RETURNDATE_EXCEL:
                return (float) $endDate;
            case Functions::RETURNDATE_PHP_NUMERIC:
                return (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp($endDate);
            case Functions::RETURNDATE_PHP_OBJECT:
                return \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($endDate);
        }
    }


    /**
     * DAYOFMONTH
     *
     * Returns the day of the month, for a specified date. The day is given as an integer
     * ranging from 1 to 31.
     *
     * Excel Function:
     *        DAY(dateValue)
     *
     * @param    mixed    $dateValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @return    int        Day of the month
     */
    public static function DAYOFMONTH($dateValue = 1)
    {
        $dateValue    = Functions::flattenSingleValue($dateValue);

        if ($dateValue === null) {
            $dateValue = 1;
        } elseif (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        } elseif ($dateValue == 0.0) {
            return 0;
        } elseif ($dateValue < 0.0) {
            return Functions::NAN();
        }

        // Execute function
        $PHPDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);

        return (int) $PHPDateObject->format('j');
    }


    /**
     * DAYOFWEEK
     *
     * Returns the day of the week for a specified date. The day is given as an integer
     * ranging from 0 to 7 (dependent on the requested style).
     *
     * Excel Function:
     *        WEEKDAY(dateValue[,style])
     *
     * @param    mixed    $dateValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @param    int        $style            A number that determines the type of return value
     *                                        1 or omitted    Numbers 1 (Sunday) through 7 (Saturday).
     *                                        2                Numbers 1 (Monday) through 7 (Sunday).
     *                                        3                Numbers 0 (Monday) through 6 (Sunday).
     * @return    int        Day of the week value
     */
    public static function DAYOFWEEK($dateValue = 1, $style = 1)
    {
        $dateValue    = Functions::flattenSingleValue($dateValue);
        $style        = Functions::flattenSingleValue($style);

        if (!is_numeric($style)) {
            return Functions::VALUE();
        } elseif (($style < 1) || ($style > 3)) {
            return Functions::NAN();
        }
        $style = floor($style);

        if ($dateValue === null) {
            $dateValue = 1;
        } elseif (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        } elseif ($dateValue < 0.0) {
            return Functions::NAN();
        }

        // Execute function
        $PHPDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
        $DoW = $PHPDateObject->format('w');

        $firstDay = 1;
        switch ($style) {
            case 1:
                ++$DoW;
                break;
            case 2:
                if ($DoW == 0) {
                    $DoW = 7;
                }
                break;
            case 3:
                if ($DoW == 0) {
                    $DoW = 7;
                }
                $firstDay = 0;
                --$DoW;
                break;
        }
        if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_EXCEL) {
            //    Test for Excel's 1900 leap year, and introduce the error as required
            if (($PHPDateObject->format('Y') == 1900) && ($PHPDateObject->format('n') <= 2)) {
                --$DoW;
                if ($DoW < $firstDay) {
                    $DoW += 7;
                }
            }
        }

        return (int) $DoW;
    }


    /**
     * WEEKOFYEAR
     *
     * Returns the week of the year for a specified date.
     * The WEEKNUM function considers the week containing January 1 to be the first week of the year.
     * However, there is a European standard that defines the first week as the one with the majority
     * of days (four or more) falling in the new year. This means that for years in which there are
     * three days or less in the first week of January, the WEEKNUM function returns week numbers
     * that are incorrect according to the European standard.
     *
     * Excel Function:
     *        WEEKNUM(dateValue[,style])
     *
     * @param    mixed    $dateValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @param    boolean    $method            Week begins on Sunday or Monday
     *                                        1 or omitted    Week begins on Sunday.
     *                                        2                Week begins on Monday.
     * @return    int        Week Number
     */
    public static function WEEKOFYEAR($dateValue = 1, $method = 1)
    {
        $dateValue    = Functions::flattenSingleValue($dateValue);
        $method        = Functions::flattenSingleValue($method);

        if (!is_numeric($method)) {

This code seems to be duplicated across your project.

            return Functions::VALUE();
        } elseif (($method < 1) || ($method > 2)) {
            return Functions::NAN();
        }
        $method = floor($method);

        if ($dateValue === null) {
            $dateValue = 1;
        } elseif (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        } elseif ($dateValue < 0.0) {
            return Functions::NAN();
        }

        // Execute function
        $PHPDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);
        $dayOfYear = $PHPDateObject->format('z');
        $PHPDateObject->modify('-' . $dayOfYear . ' days');
        $dow = $PHPDateObject->format('w');
        $daysInFirstWeek = 7 - (($dow + (2 - $method)) % 7);
        $dayOfYear -= $daysInFirstWeek;
        $weekOfYear = ceil($dayOfYear / 7) + 1;

        return (int) $weekOfYear;
    }


    /**
     * MONTHOFYEAR
     *
     * Returns the month of a date represented by a serial number.
     * The month is given as an integer, ranging from 1 (January) to 12 (December).
     *
     * Excel Function:
     *        MONTH(dateValue)
     *
     * @param    mixed    $dateValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @return    int        Month of the year
     */
    public static function MONTHOFYEAR($dateValue = 1)

This method seems to be duplicated in your project.

    {
        $dateValue    = Functions::flattenSingleValue($dateValue);

        if (empty($dateValue)) {
            $dateValue = 1;
        }
        if (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        } elseif ($dateValue < 0.0) {
            return Functions::NAN();
        }

        // Execute function
        $PHPDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);

        return (int) $PHPDateObject->format('n');
    }


    /**
     * YEAR
     *
     * Returns the year corresponding to a date.
     * The year is returned as an integer in the range 1900-9999.
     *
     * Excel Function:
     *        YEAR(dateValue)
     *
     * @param    mixed    $dateValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard date string
     * @return    int        Year
     */
    public static function YEAR($dateValue = 1)

This method seems to be duplicated in your project.

    {
        $dateValue    = Functions::flattenSingleValue($dateValue);

        if ($dateValue === null) {
            $dateValue = 1;
        } elseif (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        } elseif ($dateValue < 0.0) {
            return Functions::NAN();
        }

        // Execute function
        $PHPDateObject = \PhpSpreadsheet\Shared\Date::excelToDateTimeObject($dateValue);

        return (int) $PHPDateObject->format('Y');
    }


    /**
     * HOUROFDAY
     *
     * Returns the hour of a time value.
     * The hour is given as an integer, ranging from 0 (12:00 A.M.) to 23 (11:00 P.M.).
     *
     * Excel Function:
     *        HOUR(timeValue)
     *
     * @param    mixed    $timeValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard time string
     * @return    int        Hour
     */
    public static function HOUROFDAY($timeValue = 0)

This method seems to be duplicated in your project.

    {
        $timeValue    = Functions::flattenSingleValue($timeValue);

        if (!is_numeric($timeValue)) {
            if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_GNUMERIC) {
                $testVal = strtok($timeValue, '/-: ');
                if (strlen($testVal) < strlen($timeValue)) {
                    return Functions::VALUE();
                }
            }
            $timeValue = self::getTimeValue($timeValue);

It seems like $timeValue defined by self::getTimeValue($timeValue) on line 1368 can also be of type boolean or null or object; however, PhpSpreadsheet\Calculation\DateTime::getTimeValue() does only seem to accept string, maybe add an additional type check?

            if (is_string($timeValue)) {
                return Functions::VALUE();
            }
        }
        // Execute function
        if ($timeValue >= 1) {
            $timeValue = fmod($timeValue, 1);
        } elseif ($timeValue < 0.0) {
            return Functions::NAN();
        }
        $timeValue = \PhpSpreadsheet\Shared\Date::excelToTimestamp($timeValue);

        return (int) gmdate('G', $timeValue);
    }


    /**
     * MINUTEOFHOUR
     *
     * Returns the minutes of a time value.
     * The minute is given as an integer, ranging from 0 to 59.
     *
     * Excel Function:
     *        MINUTE(timeValue)
     *
     * @param    mixed    $timeValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard time string
     * @return    int        Minute
     */
    public static function MINUTEOFHOUR($timeValue = 0)

This method seems to be duplicated in your project.

    {
        $timeValue = $timeTester    = Functions::flattenSingleValue($timeValue);

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

        if (!is_numeric($timeValue)) {
            if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_GNUMERIC) {
                $testVal = strtok($timeValue, '/-: ');
                if (strlen($testVal) < strlen($timeValue)) {
                    return Functions::VALUE();
                }
            }
            $timeValue = self::getTimeValue($timeValue);

It seems like $timeValue defined by self::getTimeValue($timeValue) on line 1409 can also be of type boolean or null or object; however, PhpSpreadsheet\Calculation\DateTime::getTimeValue() does only seem to accept string, maybe add an additional type check?

            if (is_string($timeValue)) {
                return Functions::VALUE();
            }
        }
        // Execute function
        if ($timeValue >= 1) {
            $timeValue = fmod($timeValue, 1);
        } elseif ($timeValue < 0.0) {
            return Functions::NAN();
        }
        $timeValue = \PhpSpreadsheet\Shared\Date::excelToTimestamp($timeValue);

        return (int) gmdate('i', $timeValue);
    }


    /**
     * SECONDOFMINUTE
     *
     * Returns the seconds of a time value.
     * The second is given as an integer in the range 0 (zero) to 59.
     *
     * Excel Function:
     *        SECOND(timeValue)
     *
     * @param    mixed    $timeValue        Excel date serial value (float), PHP date timestamp (integer),
     *                                    PHP DateTime object, or a standard time string
     * @return    int        Second
     */
    public static function SECONDOFMINUTE($timeValue = 0)

This method seems to be duplicated in your project.

    {
        $timeValue    = Functions::flattenSingleValue($timeValue);

        if (!is_numeric($timeValue)) {
            if (Functions::getCompatibilityMode() == Functions::COMPATIBILITY_GNUMERIC) {
                $testVal = strtok($timeValue, '/-: ');
                if (strlen($testVal) < strlen($timeValue)) {
                    return Functions::VALUE();
                }
            }
            $timeValue = self::getTimeValue($timeValue);

It seems like $timeValue defined by self::getTimeValue($timeValue) on line 1450 can also be of type boolean or null or object; however, PhpSpreadsheet\Calculation\DateTime::getTimeValue() does only seem to accept string, maybe add an additional type check?

            if (is_string($timeValue)) {
                return Functions::VALUE();
            }
        }
        // Execute function
        if ($timeValue >= 1) {
            $timeValue = fmod($timeValue, 1);
        } elseif ($timeValue < 0.0) {
            return Functions::NAN();
        }
        $timeValue = \PhpSpreadsheet\Shared\Date::excelToTimestamp($timeValue);

        return (int) gmdate('s', $timeValue);
    }


    /**
     * EDATE
     *
     * Returns the serial number that represents the date that is the indicated number of months
     * before or after a specified date (the start_date).
     * Use EDATE to calculate maturity dates or due dates that fall on the same day of the month
     * as the date of issue.
     *
     * Excel Function:
     *        EDATE(dateValue,adjustmentMonths)
     *
     * @param    mixed    $dateValue            Excel date serial value (float), PHP date timestamp (integer),
     *                                        PHP DateTime object, or a standard date string
     * @param    int        $adjustmentMonths    The number of months before or after start_date.
     *                                        A positive value for months yields a future date;
     *                                        a negative value yields a past date.
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function EDATE($dateValue = 1, $adjustmentMonths = 0)
    {
        $dateValue            = Functions::flattenSingleValue($dateValue);
        $adjustmentMonths    = Functions::flattenSingleValue($adjustmentMonths);

        if (!is_numeric($adjustmentMonths)) {
            return Functions::VALUE();
        }
        $adjustmentMonths = floor($adjustmentMonths);

        if (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        }

        // Execute function
        $PHPDateObject = self::adjustDateByMonths($dateValue, $adjustmentMonths);

        switch (Functions::getReturnDateType()) {

This code seems to be duplicated across your project.

            case Functions::RETURNDATE_EXCEL:
                return (float) \PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject);

$PHPDateObject is of type object<DateTime>, but the function expects a integer.

            case Functions::RETURNDATE_PHP_NUMERIC:
                return (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp(\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject));

$PHPDateObject is of type object<DateTime>, but the function expects a integer.

\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject) is of type double|false, but the function expects a integer.

            case Functions::RETURNDATE_PHP_OBJECT:
                return $PHPDateObject;
        }
    }


    /**
     * EOMONTH
     *
     * Returns the date value for the last day of the month that is the indicated number of months
     * before or after start_date.
     * Use EOMONTH to calculate maturity dates or due dates that fall on the last day of the month.
     *
     * Excel Function:
     *        EOMONTH(dateValue,adjustmentMonths)
     *
     * @param    mixed    $dateValue            Excel date serial value (float), PHP date timestamp (integer),
     *                                        PHP DateTime object, or a standard date string
     * @param    int        $adjustmentMonths    The number of months before or after start_date.
     *                                        A positive value for months yields a future date;
     *                                        a negative value yields a past date.
     * @return    mixed    Excel date/time serial value, PHP date/time serial value or PHP date/time object,
     *                        depending on the value of the ReturnDateType flag
     */
    public static function EOMONTH($dateValue = 1, $adjustmentMonths = 0)
    {
        $dateValue            = Functions::flattenSingleValue($dateValue);
        $adjustmentMonths    = Functions::flattenSingleValue($adjustmentMonths);

        if (!is_numeric($adjustmentMonths)) {
            return Functions::VALUE();
        }
        $adjustmentMonths = floor($adjustmentMonths);

        if (is_string($dateValue = self::getDateValue($dateValue))) {
            return Functions::VALUE();
        }

        // Execute function
        $PHPDateObject = self::adjustDateByMonths($dateValue, $adjustmentMonths+1);
        $adjustDays = (int) $PHPDateObject->format('d');
        $adjustDaysString = '-' . $adjustDays . ' days';
        $PHPDateObject->modify($adjustDaysString);

        switch (Functions::getReturnDateType()) {

This code seems to be duplicated across your project.

            case Functions::RETURNDATE_EXCEL:
                return (float) \PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject);

$PHPDateObject is of type object<DateTime>, but the function expects a integer.

            case Functions::RETURNDATE_PHP_NUMERIC:
                return (integer) \PhpSpreadsheet\Shared\Date::excelToTimestamp(\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject));

$PHPDateObject is of type object<DateTime>, but the function expects a integer.

\PhpSpreadsheet\Shared\Date::PHPToExcel($PHPDateObject) is of type double|false, but the function expects a integer.

            case Functions::RETURNDATE_PHP_OBJECT:
                return $PHPDateObject;
        }
    }
}