DateTime Type: objet Propriétés: + modify(string s) + string format(string f) Exemples: // current date was 2011-11-08 $myDate = new DateTime(); $myDate->modify('+100 years'); var_dump($myDate->format('Y-m-d')); // string(10) "2111-11-08" $myDate = new DateTime(); $myDate->modify('+100 days'); var_dump($myDate->format('Y-m-d')); // string(10) "2012-02-16" // adding/substracting months is not reliable for daily script // see the note on secure.php.net/manual/en/datetime.formats.relative.php $d = new DateTime('2018-03-31'); $d->modify('-1 month'); echo $d->format('Y-m-d'); // 2018-03-03 $d = new DateTime('2018-04-03'); $d->modify('-1 month'); echo $d->format('Y-m-d'); // 2018-03-03 Liens: secure.php.net/manual/en/datetime.modify.php