#41547 [Opn->Bgs]: strtotime bug

ID: 41547 Updated by: derick@php.net Reported By: noisex at apollo dot lv -Status: Open +Status: Bogus Bug Type: Date/time related Operating System: FreeBSD 6.2 PHP Version: 5.2.2 New Comment: Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php Your are incorrect in your assessment. The "+-n months" statement goes back one month. Back from May 31st that becomes April 31st. As April only has 30 days this turns into May 1st. The same is true February, which only has 28 days, so the result is March 3rd. See the following script: <?php for($i=1; $i<=12; $i++) { echo date("Y-M-d H:i:s",strtotime("-$i months"))."<br/>\n"; } ?> Previous Comments: ------------------------------------------------------------------------ [2007-05-31 09:25:19] noisex at apollo dot lv The result must be (sorry): 2007-Apr 2007-Mar 2007-Feb 2007-Jan 2006-Dec 2006-Nov 2006-Oct 2006-Sep 2006-Aug 2006-Jul 2006-Jun 2006-May ------------------------------------------------------------------------ [2007-05-31 09:21:33] noisex at apollo dot lv Description: ------------ On months with 31th day the strtotime function with +/-$foo month calculates wrong. it calculates -30 days not 31 days. Reproduce code: --------------- Simple example (running today 31 May): <?php for($i=1; $i<=12; $i++) { echo date("Y-M",strtotime("-$i months"))."<br>"; } ?> Expected result: ---------------- 2007-Mar 2007-Feb 2007-Jan 2006-Dec 2006-Nov 2006-Oct 2006-Sep 2006-Aug 2006-Jul 2006-Jun 2006-May 2006-Apr Actual result: -------------- 2007-May 2007-Mar 2007-Mar 2007-Jan 2006-Dec 2006-Dec 2006-Oct 2006-Oct 2006-Aug 2006-Jul 2006-Jul 2006-May ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=41547&edit=1