PHP 日期一个月时间错误

1. 时间“2020-05-12 09:00:00”，加一个月

$time1 = strtotime("2020-05-12 09:00:00");
echo date( "Y-m-d H:i:s", strtotime( "+1 months", $time1 ) );//2020-06-12 09:00:00[正确]

2. 时间“2020-01-31 09:00:00”，加一个月

$time2 = strtotime("2020-01-31 09:00:00");
echo date( "Y-m-d H:i:s", strtotime( "+1 month", $time2 ) );//2020-03-02 09:00:00[错误]

解决办法：

function get_date($timeDate,$time)
{
    //智能的判断一个月份的最后一天是几号  first day of/last day of  -1 month
    echo date("Y-m-d H:i:s", strtotime($timeDate." last day of {$time}"));
}