public static function jDateTime::jalaliCal in Persian Date for Drupal 8 8.4

This function determines if the Jalaali (Persian) year is leap (366-day long) or is the common year (365 days), and finds the day in March (Gregorian calendar) of the first day of the Jalaali year (jy).

@see: http://www.astro.uni.torun.pl/~kb/Papers/EMP/PersianC-EMP.htm @see: http://www.fourmilab.ch/documents/calendar/

Parameters

int $jy Jalaali calendar year (-61 to 3177):

Return value

array leap: number of years since the last leap year (0 to 4) gy: Gregorian year of the beginning of Jalaali year march: the March day of Farvardin the 1st (1st day of jy)

2 calls to jDateTime::jalaliCal()

jDateTime::d2j in src/Library/Jalali/jDateTime.php

Converts the Julian Day number to a date in the Jalaali calendar.

jDateTime::j2d in src/Library/Jalali/jDateTime.php

Converts a date of the Jalaali calendar to the Julian Day number.

File

src/Library/Jalali/jDateTime.php, line 143

Class

jDateTime

Class jDateTime @package Morilog\Jalali

Namespace

Drupal\persian_date\Library\Jalali

Code

public static function jalaliCal($jy) {
  $breaks = [
    -61,
    9,
    38,
    199,
    426,
    686,
    756,
    818,
    1111,
    1181,
    1210,
    1635,
    2060,
    2097,
    2192,
    2262,
    2324,
    2394,
    2456,
    3178,
  ];
  $breaksCount = count($breaks);
  $gy = $jy + 621;
  $leapJ = -14;
  $jp = $breaks[0];
  if ($jy < $jp || $jy >= $breaks[$breaksCount - 1]) {
    throw new \InvalidArgumentException('Invalid Jalali year : ' . $jy);
  }
  $jump = 0;
  for ($i = 1; $i < $breaksCount; $i += 1) {
    $jm = $breaks[$i];
    $jump = $jm - $jp;
    if ($jy < $jm) {
      break;
    }
    $leapJ = $leapJ + self::div($jump, 33) * 8 + self::div(self::mod($jump, 33), 4);
    $jp = $jm;
  }
  $n = $jy - $jp;
  $leapJ = $leapJ + self::div($n, 33) * 8 + self::div(self::mod($n, 33) + 3, 4);
  if (self::mod($jump, 33) === 4 && $jump - $n === 4) {
    $leapJ += 1;
  }
  $leapG = self::div($gy, 4) - self::div((self::div($gy, 100) + 1) * 3, 4) - 150;
  $march = 20 + $leapJ - $leapG;
  if ($jump - $n < 6) {
    $n = $n - $jump + self::div($jump + 4, 33) * 33;
  }
  $leap = self::mod(self::mod($n + 1, 33) - 1, 4);
  if ($leap === -1) {
    $leap = 4;
  }
  return [
    'leap' => $leap,
    'gy' => $gy,
    'march' => $march,
  ];
}