function jalali_to_gregorian($j_y, $j_m, $j_d)
{
$g_days_in_month = array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
$j_days_in_month = array(31, 31, 31, 31, 31, 31, 30, 30, 30, 30, 30, 29);
$jy = $j_y - 979;
$jm = $j_m - 1;
$jd = $j_d - 1;
$j_day_no = 365 * $jy + JalaliCalendar::div($jy, 33) * 8 + JalaliCalendar::div($jy % 33 + 3, 4);
for ($i = 0; $i < $jm; ++$i) {
$j_day_no += $j_days_in_month[$i];
}
$j_day_no += $jd;
$g_day_no = $j_day_no + 79;
$gy = 1600 + 400 * JalaliCalendar::div($g_day_no, 146097);
/* 146097 = 365*400 + 400/4 - 400/100 + 400/400 */
$g_day_no = $g_day_no % 146097;
$leap = true;
if ($g_day_no >= 36525) {
$g_day_no--;
$gy += 100 * JalaliCalendar::div($g_day_no, 36524);
/* 36524 = 365*100 + 100/4 - 100/100 */
$g_day_no = $g_day_no % 36524;
if ($g_day_no >= 365) {
$g_day_no++;
} else {
$leap = false;
}
}
$gy += 4 * JalaliCalendar::div($g_day_no, 1461);
/* 1461 = 365*4 + 4/4 */
$g_day_no %= 1461;
if ($g_day_no >= 366) {
$leap = false;
$g_day_no--;
$gy += JalaliCalendar::div($g_day_no, 365);
$g_day_no = $g_day_no % 365;
}
for ($i = 0; $g_day_no >= $g_days_in_month[$i] + ($i == 1 && $leap); $i++) {
$g_day_no -= $g_days_in_month[$i] + ($i == 1 && $leap);
}
$gm = $i + 1;
$gd = $g_day_no + 1;
return array($gy, $gm, $gd);
}
