Doc #60353 [NEW]: Date-related "Relative Formats" doesn't indicate month behaviour

From: Operating system: PHP version: Irrelevant Package: Documentation problem Bug Type: Documentation Problem Bug description:Date-related "Relative Formats" doesn't indicate month behaviour Description: ------------ A fellow on reddit.com/r/PHP mentioned that the documentation for Relative Formats for dates is missing information on how relative months work. Here's the relevant comment: http://www.reddit.com/r/PHP/comments/mk3ub/strtotime_wtf/c31lhav "echo date("Y-m-d", strtotime("+1 month 2011-11-30")); returns: 2011-12-30 // wtf? but I wanted 2011-12-31 This is why you don't use months when calculating dates. A month is ambiguous. Think about it - since months vary, which month is it supposed to use to calculate 1 month? November or December? Since The starting date is in November, it assumes that is the first month it should start calculating from. So, for the first iteration, 1 month is 30 days. However, it recalculates what a month is for every iteration. consider this: echo date("Y-m-d", strtotime("+1 month 2011-11-30")); // 2011-12-30 or 30 days echo date("Y-m-d", strtotime("+2 month 2011-11-30")); // 2012-01-30 or 61 days echo date("Y-m-d", strtotime("+30 days 2011-11-30")); // 2011-12-30 echo date("Y-m-d", strtotime("+60 days 2011-11-30")); // 2012-01-29 Notice how when I use +2 months it suddenly becomes 61 days. This is because it starts in December on the second iteration, and it recalculates what a month is based on that." This behaviour should be documented in the datetime.formats.relative document. -- Edit bug report at https://bugs.php.net/bug.php?id=60353&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=60353&r=trysnapshot54 Try a snapshot (PHP 5.3): https://bugs.php.net/fix.php?id=60353&r=trysnapshot53 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=60353&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=60353&r=fixed Fixed in SVN and need be documented: https://bugs.php.net/fix.php?id=60353&r=needdocs Fixed in release: https://bugs.php.net/fix.php?id=60353&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=60353&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=60353&r=needscript Try newer version: https://bugs.php.net/fix.php?id=60353&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=60353&r=support Expected behavior: https://bugs.php.net/fix.php?id=60353&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=60353&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=60353&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=60353&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=60353&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=60353&r=dst IIS Stability: https://bugs.php.net/fix.php?id=60353&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=60353&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=60353&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=60353&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=60353&r=mysqlcfg