Bug #77571 [Com]: DateInterval has incorrect interval using timezones from UTC+01:00 to UTC+12:00

Edit report at https://bugs.php.net/bug.php?id=77571&edit=1 ID: 77571 Comment by: a at b dot c dot de Reported by: techouse at gmail dot com Summary: DateInterval has incorrect interval using timezones from UTC+01:00 to UTC+12:00 Status: Open Type: Bug Package: Date/time related Operating System: macOS 10.14.3, Ubuntu 18.04 PHP Version: 7.3.1, 7.2.10 Block user comment: N Private report: N New Comment: May also be related to bug #76374 Previous Comments: ------------------------------------------------------------------------ [2019-02-06 08:55:48] techouse at gmail dot com Might be related to https://bugs.php.net/bug.php?id=52480 ------------------------------------------------------------------------ [2019-02-06 08:22:05] techouse at gmail dot com Better summary ------------------------------------------------------------------------ [2019-02-06 08:20:45] techouse at gmail dot com Updated the summary to be more descriptive and added another tested PHP version. ------------------------------------------------------------------------ [2019-02-05 15:26:37] techouse at gmail dot com Description: ------------ Yesterday I observed a weird DateInterval bug where adding 5 weeks would always equal 35 days but the difference in months and days would not be correct. After some digging I figured out it was related to timezones and only affected timezones ranging from Europe/London eastward all the way to Pacific/Auckland, however as soon as I used Pacific/Honolulu the issue was gone. Test findings All the tests in tests/Timezones/America and tests/Timezones/Atlantic pass. Another weird thing is that Europe/London passes all tests where it does not adhere to daylight savings time (UTC+01:00). From this I draw a conclusion that all timezones that are greater than UTC+00:00 fail because of this additional time. All the tests and findings can be found in my GitHub repo https://github.com/techouse/php-date-interval-timezone-bug Test script: --------------- https://github.com/techouse/php-date-interval-timezone-bug Expected result: ---------------- A correct DateInterval. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=77571&edit=1