Count number of month from date to date

If you have two date and want to count number of month between them, following is function to count this.

public function countMonthFromDate($date){    

    $date1 = $date;    

    $date2 = date('Y-m-d');
    $ts1 = strtotime($date1);

    $ts2 = strtotime($date2);
    $year1 = date('Y', $ts1);

    $year2 = date('Y', $ts2);
    $month1 = date('m', $ts1);

    $month2 = date('m', $ts2);
    $diff = (($year2 - $year1) * 12) + ($month2 - $month1);    

     return $diff;

}