Question

If I have a PHP string in the format of mm-dd-YYYY (for example, 10-16-2003), how do I properly convert that to a Date and then a DateTime in the format of YYYY-mm-dd? The only reason I ask for both Date and DateTime is because I need one in one spot, and the other in a different spot.

Answer 1

Use strtotime() on your first date then date('Y-m-d') to convert it back:

$time = strtotime('10/16/2003');

$newformat = date('Y-m-d',$time);

echo $newformat;
// 2003-10-16

Make note that there is a difference between using forward slash / and hyphen - in the strtotime() function. To quote from php.net:

Dates in the m/d/y or d-m-y formats
are disambiguated by looking at the
separator between the various
components: if the separator is a
slash (/), then the American m/d/y is
assumed; whereas if the separator is a
dash (-) or a dot (.), then the
European d-m-y format is assumed.

To avoid potential ambiguity, it’s best to use ISO 8601 (YYYY-MM-DD) dates or DateTime::createFromFormat() when possible.