php function to convert date from jalali to gregorian

php function to convert date from jalali to gregorian

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 + div($jy, 33)*8 + div($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;

$gy = 1600 + 400*div($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) /* 36525 = 365*100 + 100/4 */

{

$g_day_no--;

$gy += 100*div($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;

}

$gy += 4*div($g_day_no, 1461); /* 1461 = 365*4 + 4/4 */

$g_day_no %= 1461;

if ($g_day_no >= 366) {

$leap = false;

$g_day_no--;

$gy += div($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);

}