note 112675 added to dateinterval.construct

M is used to indicate both months and minutes. As noted on the referenced wikipedia page for ISO 6801 http://en.wikipedia.org/wiki/Iso8601#Durations To resolve ambiguity, "P1M" is a one-month duration and "PT1M" is a one-minute duration (note the time designator, T, that precedes the time value). Using: PHP 5.3.2-1ubuntu4.19 // For 3 Months $dateTime = new DateTime;echo $dateTime->format( DateTime::ISO8601 ), PHP_EOL; $dateTime->add(new DateInterval("P3M")); echo $dateTime->format( DateTime::ISO8601 ), PHP_EOL; Results in: 2013-07-11T11:12:26-0400 2013-10-11T11:12:26-0400 // For 3 Minutes $dateTime = new DateTime;echo $dateTime->format( DateTime::ISO8601 ), PHP_EOL; $dateTime->add(new DateInterval("PT3M")); echo $dateTime->format( DateTime::ISO8601 ), PHP_EOL; Results in: 2013-07-11T11:12:42-0400 2013-07-11T11:15:42-0400 Insert a T after the P in the interval to add 3 minutes instead of 3 months. ---- Server IP: 69.147.83.199 Probable Submitter: 71.183.18.83 ---- Manual Page -- http://php.net/manual/en/dateinterval.construct.php Edit -- https://master.php.net/note/edit/112675 Del: integrated -- https://master.php.net/note/delete/112675/integrated Del: useless -- https://master.php.net/note/delete/112675/useless Del: bad code -- https://master.php.net/note/delete/112675/bad+code Del: spam -- https://master.php.net/note/delete/112675/spam Del: non-english -- https://master.php.net/note/delete/112675/non-english Del: in docs -- https://master.php.net/note/delete/112675/in+docs Del: other reasons-- https://master.php.net/note/delete/112675 Reject -- https://master.php.net/note/reject/112675 Search -- https://master.php.net/manage/user-notes.php