note 126892 added to datetime.diff

There is an interesting quirk around leap days. If the first date is a leap date (29th February in a leap year) and the second date is not a leap year, the results may not be what you expect: <?php $tz = new DateTimeZone('UTC'); $dt1 = new DateTime('2012-02-29 13:00:00', $tz); $dt2 = new DateTime('2013-03-01 12:00:00', $tz); print $dt1->diff($dt2)->format('%r%y years, %m months, %d days, %h hours, %i minutes, %s seconds'); /* Output: 0 years, 11 months, 30 days, 23 hours, 0 minutes, 0 seconds */ ?> If you reverse the order of the dates you get: <?php print $dt2->diff($dt1)->format('%r%y years, %m months, %d days, %h hours, %i minutes, %s seconds'); /* Output: -1 years, 0 months, 0 days, 23 hours, 0 minutes, 0 seconds */ ?> ---- Server IP: 45.112.84.4 Probable Submitter: 80.90.5.135 (proxied: 2001:8003:43b0:9e01:b8a3:4bf2:7da5:cc9f) ---- Manual Page -- https://php.net/manual/en/datetime.diff.php Edit -- https://main.php.net/note/edit/126892 Del: integrated -- https://main.php.net/note/delete/126892/integrated Del: useless -- https://main.php.net/note/delete/126892/useless Del: bad code -- https://main.php.net/note/delete/126892/bad+code Del: spam -- https://main.php.net/note/delete/126892/spam Del: non-english -- https://main.php.net/note/delete/126892/non-english Del: in docs -- https://main.php.net/note/delete/126892/in+docs Del: other reasons-- https://main.php.net/note/delete/126892 Reject -- https://main.php.net/note/reject/126892 Search -- https://main.php.net/manage/user-notes.php