note 91977 modified in datetime.modify by danbrown
| From: | danbrown@php.net | Date: | Fri, 03 Jul 2009 13:07:04 +0000 |
| Subject: | note 91977 modified in datetime.modify by danbrown | ||
| References: | 1 | Groups: | php.notes |
| Request: | Send a blank email to php-notes+get-157875@lists.php.net to get a copy of this message | ||
Do not use '[+/-]{n} month' to get the last day of the month.
If you use '+1 month' on the first of the month, it sets the date to the next first of the
month. This behaviour gives the impression, that php considers the length of a month, which is not
true.
Basically if you use '+1 month' it takes the month number, adds 1 and parses result as a
new date. But if you use '+1 month' on the last day of a month, the result is unexpected
as 2009-05-31 becomes 2009-06-31 which is an invalid date and then interpreted as 2009-07-01.
--was--
Do not use '[+/-]{n} month' to get the last day
of the month.
If you use '+1 month' on the first of the month,
it sets the date to the next first of the month.
This behaviour gives the impression, that php
considers the length of a month, which is not true.
Basically if you use '+1 month' it takes the
month number, adds 1 and parses result as a
new date.
But if you use '+1 month' on the last day of
a month, the result is unexpected as 2009-05-31
becomes 2009-06-31 which is an invalid date and
then interpreted as 2009-07-01.
http://php.net/manual/en/datetime.modify.php