Bug #72243 [Com]: DateTimes fail to compare correctly when a DateTimeZone is set

Edit report at https://bugs.php.net/bug.php?id=72243&edit=1 ID: 72243 Comment by: Rican7 at gmail dot com Reported by: Rican7 at gmail dot com Summary: DateTimes fail to compare correctly when a DateTimeZone is set Status: Open Type: Bug Package: Date/time related PHP Version: 7.0.6 Block user comment: N Private report: N New Comment: These 3v4l scripts show the bug in action: - Broken (TZ abbreviation): https://3v4l.org/WkjAA - Working (IANA TZ): https://3v4l.org/MDqHr Previous Comments: ------------------------------------------------------------------------ [2016-05-19 18:13:59] Rican7 at gmail dot com Description: ------------ DateTime instances are supposed to be natively "comparable" (using ==, >, <, etc). Unfortunately, a colleague and I just noticed that if a Time Zone is updated on a compared instance, than the comparison fails... but only if the time zone isn't an IANA identifier. Really strange. What's worse, is that it seems to "magically" start to work again if a (seemingly idempotent) getTimestamp() call is made on the instance that had the new time-zone applied. Is this due to a lazy calculation of the internal timestamp that isn't getting validated when a new time zone is applied? Test script: --------------- <?php $datetime = new DateTime(null, new DateTimeZone('UTC')); $datetime_2 = clone $datetime; $datetime_2->add(new DateInterval('PT2S')); var_dump($datetime < $datetime_2); var_dump($datetime->getTimestamp() < $datetime_2->getTimestamp()); $datetime_2->setTimezone(new DateTimeZone('EST')); var_dump($datetime < $datetime_2); var_dump($datetime->getTimestamp() < $datetime_2->getTimestamp()); // Now that getTimestamp() has been called, it'll "magically" work... var_dump($datetime < $datetime_2); Expected result: ---------------- bool(true) bool(true) bool(true) bool(true) bool(true) Actual result: -------------- bool(true) bool(true) bool(false) bool(true) bool(true) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=72243&edit=1