时间计算

1、时间差

一、月份
    ①
    $start = new DateTime('2018-11-20');
    $end =  new DateTime('2019-11-15');
    $diff = $start->diff($end);
    $diff_month = $diff->format('%y')*12+$diff->format('%m');
    echo $diff_month;
    ②
    function getMonthNum($date1,$date2){
        $date1_stamp=strtotime($date1);
        $date2_stamp=strtotime($date2);
        list($date_1['y'],$date_1['m'])=explode("-",date('Y-m',$date1_stamp));
        list($date_2['y'],$date_2['m'])=explode("-",date('Y-m',$date2_stamp));
        return abs($date_1['y']-$date_2['y'])*12 +$date_2['m']-$date_1['m'];
    }
    echo getMonthNum('2018-11-20','2019-11-15');
二、、天数
    $datetime_start = new DateTime('2018-11-20');
    $datetime_end =  new DateTime('2019-10-15');
    $diff = $datetime_start->diff($datetime_end);
    $service_cycle = $datetime_start->diff($datetime_end)->days;
    echo $service_cycle;