How to subtract 4 months from today's date?

问题

I need to declare two dates in "Ymd" format: $toDate and $fromDate.

$toDate represents today's date and $fromDate needs to be 4 months earlier than today.

$toDate = Date('Ymd');
$fromDate = ?

How do I create $fromDate?

回答1:

Use the magic of strtotime:

$fromDate = date("Ymd", strtotime("-4 months"));

回答2:

see the code below...

$fourmonthsback = date("Ymd", mktime(0, 0, 0, date("m")-4, date("d"),   date("Y")));

OR

$fourmonthsback = mktime(0, 0, 0, date("m")-4, date("d"),   date("Y"));

来源：https://stackoverflow.com/questions/4163387/how-to-subtract-4-months-from-todays-date