1--TEST-- 2Bug #73858: diff() of two relative/described DateTimes is wrong 3--FILE-- 4<?php 5/* 6In the "verbose setup method" I'm trying setup the DateTime object myself 7to see if it's the format string which is parsed in correctly or if it's the DateTime 8object which is breaking stuff. From the testing it appears DateTime is broken somehow. 9*/ 10$ss = 'february first day of last month midnight'; 11$es = 'february first day of this month midnight - 1 second'; 12 13$s = new DateTime($ss); 14$e = new DateTime($es); 15$d= $e->diff($s); 16var_dump($d->days); // 0 ... but should be 30 17 18$s = (new DateTime(null))->setTimestamp(strtotime($ss)); // verbose setup method 19$e = (new DateTime(null))->setTimestamp(strtotime($es)); // verbose setup method 20$d = $e->diff($s); 21var_dump($d->days); // 30 ... and should be 30 22 23/* 24Next we will try mix/match the code to see what happens, surprisingly it seems that the end date ($e) 25is the important one, if it uses the verbose method it returns the correct values. 26*/ 27$s = (new DateTime(null))->setTimestamp(strtotime($ss)); // verbose setup method 28$e = new DateTime($es); 29$d= $e->diff($s); 30var_dump($d->days); // 0 ... but should be 30 31 32$s = new DateTime($ss); 33$e = (new DateTime(null))->setTimestamp(strtotime($es)); // verbose setup method 34$d= $e->diff($s); 35var_dump($d->days); // 30 ... and should be 30 36 37/* 38This test just proves that the $e date is important BUT NOT because it's the one we call the diff() method 39on, that's just coincidental that seems to imply that the "- 1 second" in the date string is the problem. 40*/ 41$s = new DateTime($ss); 42$e = (new DateTime(null))->setTimestamp(strtotime($es)); // verbose setup method 43$d= $s->diff($e); 44var_dump($d->days); // 30 ... and should be 30 45 46/* 47[Workaround] 48This final test seems to prove that the input string is important and that the "- 1 second" has a negative knock-on 49effect on the results of the diff. By modifying the datetime with ->modify everything works as expected ... 50it just means you have to be careful of how we work with DateTimes . 51*/ 52$s = new DateTime($ss); 53$e = new DateTime('february first day of this month midnight'); 54$e->modify('- 1 second'); 55var_dump($e->diff($s)->days); // 30 ... and should be 30 56?> 57--EXPECT-- 58int(30) 59int(30) 60int(30) 61int(30) 62int(30) 63int(30) 64