+ private static $GREG_DAYS = array( 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 );
+ private static $IRANIAN_DAYS = array( 31, 31, 31, 31, 31, 31, 30, 30, 30, 30, 30, 29 );
+ /**
+ * Algorithm by Roozbeh Pournader and Mohammad Toossi to convert
+ * Gregorian dates to Iranian dates. Originally written in C, it
+ * is released under the terms of GNU Lesser General Public
+ * License. Conversion to PHP was performed by Niklas Laxström.
+ *
+ * Link: http://www.farsiweb.info/jalali/jalali.c
+ */
+ private static function tsToIranian( $ts ) {
+ $gy = substr( $ts, 0, 4 ) -1600;
+ $gm = substr( $ts, 4, 2 ) -1;
+ $gd = substr( $ts, 6, 2 ) -1;
+
+ # Days passed from the beginning (including leap years)
+ $gDayNo = 365*$gy
+ + floor(($gy+3) / 4)
+ - floor(($gy+99) / 100)
+ + floor(($gy+399) / 400);
+
+
+ // Add days of the past months of this year
+ for( $i = 0; $i < $gm; $i++ ) {
+ $gDayNo += self::$GREG_DAYS[$i];
+ }
+
+ // Leap years
+ if ( $gm > 1 && (($gy%4===0 && $gy%100!==0 || ($gy%400==0)))) {
+ $gDayNo++;
+ }
+
+ // Days passed in current month
+ $gDayNo += $gd;
+
+ $jDayNo = $gDayNo - 79;
+
+ $jNp = floor($jDayNo / 12053);
+ $jDayNo %= 12053;
+
+ $jy = 979 + 33*$jNp + 4*floor($jDayNo/1461);
+ $jDayNo %= 1461;
+
+ if ( $jDayNo >= 366 ) {
+ $jy += floor(($jDayNo-1)/365);
+ $jDayNo = floor(($jDayNo-1)%365);
+ }
+
+ for ( $i = 0; $i < 11 && $jDayNo >= self::$IRANIAN_DAYS[$i]; $i++ ) {
+ $jDayNo -= self::$IRANIAN_DAYS[$i];
+ }
+
+ $jm= $i+1;
+ $jd= $jDayNo+1;
+
+ return array($jy, $jm, $jd);
+ }
+
+ /**
+ * Converting Gregorian dates to Hebrew dates.
+ *
+ * Based on a JavaScript code by Abu Mami and Yisrael Hersch
+ * (abu-mami@kaluach.net, http://www.kaluach.net), who permitted
+ * to translate the relevant functions into PHP and release them under
+ * GNU GPL.
+ */
+ private static function tsToHebrew( $ts ) {
+ # Parse date
+ $year = substr( $ts, 0, 4 );
+ $month = substr( $ts, 4, 2 );
+ $day = substr( $ts, 6, 2 );
+
+ # Month number when March = 1, February = 12
+ $month -= 2;
+ if( $month <= 0 ) {
+ # January of February
+ $month += 12;
+ $year--;
+ }
+
+ # Days since 1 March - calculating 30 days a month,
+ # and then adding the missing number of days
+ $day += (int)( 7 * $month / 12 + 30 * ( $month - 1 ) );
+ # Calculate Hebrew year for days after 1 Nisan
+ $hebrewYear = $year + 3760;
+ # Passover date for this year (as days since 1 March)
+ $passover = self::passoverDate( $hebrewYear );
+ if( $day <= $passover - 15 ) {
+ # Day is before 1 Nisan (passover is 15 Nisan) - it is the previous year
+ # Next year's passover (as days since 1 March)
+ $anchor = $passover;
+ # Add days since previous year's 1 March
+ $day += 365;
+ if( ( $year % 400 == 0 ) || ( $year % 100 != 0 && $year % 4 == 0 ) ) {
+ # Leap year
+ $day++;
+ }
+ # Previous year
+ $year--;
+ $hebrewYear--;
+ # Passover date for the new year (as days since 1 March)
+ $passover = self::passoverDate( $hebrewYear );
+ } else {
+ # Next year's passover (as days since 1 March)
+ $anchor = self::passoverDate( $hebrewYear + 1 );
+ }
+
+ # Days since 1 Nisan
+ $day -= $passover - 15;
+ # Difference between this year's passover date by gregorian calendar,
+ # and the next year's one + 12 days. This should be 1 days for a regular year,
+ # but 0 for incomplete one, 2 for complete, and those + 30 days of Adar I
+ # for a leap year.
+ $anchor -= $passover - 12;
+ $nextYear = $year + 1;
+ if( ( $nextYear % 400 == 0 ) || ( $nextYear % 100 != 0 && $nextYear % 4 == 0 ) ) {
+ # Next year is a leap year - difference is growing
+ $anchor++;
+ }
+
+ # Calculate day in the month from number of days sine 1 Nisan
+ # Don't check Adar - if the day is not in adar, we will stop before;
+ # if it is in adar, we will use it to check if it is Adar I or Adar II
+ for( $month = 0; $month < 11; $month++ ) {
+ # Calculate days in this month
+ if( $month == 7 && $anchor % 30 == 2 ) {
+ # Cheshvan in a complete year (otherwise as the rule below)
+ $days = 30;
+ } else if( $month == 8 && $anchor % 30 == 0 ) {
+ # Kislev in an incomplete year (otherwise as the rule below)
+ $days = 29;
+ } else {
+ # Even months have 30 days, odd have 29
+ $days = 30 - $month % 2;
+ }
+ if( $day <= $days ) {
+ # In this month
+ break;
+ }
+ # Try in next months
+ $day -= $days;
+ }
+
+ # Now we move to a year from Tishrei
+ if( $month >= 6 ) {
+ # After Tishrei, use next year
+ $hebrewYear++;
+ }
+ # Recalculate month number so that we start from Tishrei
+ $month = ( $month + 6 ) % 12 + 1;
+
+ # Fix Adar
+ if( $month == 6 && $anchor >= 30 ) {
+ # This *is* adar, and this year is leap
+ if( $day > 30 ) {
+ # Adar II
+ $month = 14;
+ $day -= 30;
+ } else {
+ # Adar I
+ $month = 13;
+ }
+ }
+
+ return array( $hebrewYear, $month, $day );
+ }
+
+ /**
+ * Based on Carl Friedrich Gauss algorithm for finding Easter date.
+ * Used for Hebrew date.
+ */
+ private static function passoverDate( $year ) {
+ $a = (int)( ( 12 * $year + 17 ) % 19 );
+ $b = (int)( $year % 4 );
+ $m = 32.044093161144 + 1.5542417966212 * $a + $b / 4.0 - 0.0031777940220923 * $year;
+ if( $m < 0 ) {
+ $m--;
+ }
+ $Mar = (int)$m;
+ if( $m < 0 ) {
+ $m++;
+ }
+ $m -= $Mar;
+
+ $c = (int)( ( $Mar + 3 * $year + 5 * $b + 5 ) % 7);
+ if( $c == 0 && $a > 11 && $m >= 0.89772376543210 ) {
+ $Mar++;
+ } else if( $c == 1 && $a > 6 && $m >= 0.63287037037037 ) {
+ $Mar += 2;
+ } else if( $c == 2 || $c == 4 || $c == 6 ) {
+ $Mar++;
+ }
+
+ $Mar += (int)( ( $year - 3760 ) / 100 ) - (int)( ( $year - 3760 ) / 400 ) - 2;
+ return $Mar;
+ }
+