PHP 3 bulan lalu
echo date("d.m.Y", strtotime("-3 Months"));
Friendly Hawk
echo date("d.m.Y", strtotime("-3 Months"));
$effectiveDate = date('Y-m-d', strtotime("+3 months", strtotime($effectiveDate)));
echo cal_days_in_month(CAL_GREGORIAN, 8, 2009);