Be carreful about this bug in php 5.6 and lower (fixed in php 7.0 and higher) :
<?php
$date = new DateTime("first day of last month");
echo $date->format('Y-m-d');
echo ' => ' ;
$date->setDate(2013, 2, 3);
echo $date->format('Y-m-d');
?>
Output <=5.6 : 2017-03-01 => 2013-02-01
Output >=7.0 : 2017-03-31 => 2013-02-03
Same goes for "Last day of last month", and the funny part, it will take the last day of the new month setted by setDate
Example with a Leap Year :
<?php
$date = new DateTime("last day of last month");
echo $date->format('Y-m-d');
echo ' => ' ;
$date->setDate(2012, 2, 3);
echo $date->format('Y-m-d');
?>
Output <=5.6 : 2017-03-31 => 2012-02-29
Output >=7.0 : 2017-03-31 => 2012-02-03
DateTime::setDate
date_date_set
(PHP 5 >= 5.2.0, PHP 7, PHP 8)
DateTime::setDate -- date_date_set — Sets the date
Description
Object-oriented style
Procedural style
Resets the current date of the DateTime object to a different date.
Like DateTimeImmutable::setDate() but works with DateTime, and changes the existing object.
The procedural version takes the DateTime object as its first argument.
Parameters
-
object -
Procedural style only: A DateTime object returned by date_create(). The function modifies this object.
-
year -
Year of the date.
-
month -
Month of the date.
-
day -
Day of the date.
Return Values
Returns the modified DateTime object for method chaining.
See Also
- DateTimeImmutable::setDate() - Sets the date
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User Contributed Notes 3 notes
kevin dot nadin at gmail dot com ¶
7 years ago
remy215 at laposte dot net ¶
12 years ago
Be warned, DateTime::setDate() does not check for invalid input.
Illustration:
<?php
$dt = new DateTime();
$dt->setDate(2012, 11, 31); // returns DateTime object and not false although this date does not exist
echo $dt->format('Y-m-d'); // output: 2012-12-01
?>
No error was generated on entering a non existing date, php silently changed it.
kevin dot nadin at gmail dot com ¶
7 years ago
Correction on the previous comment :
Bug fixed in php 7.0.17 and 7.1.3, for the version 7.0.0 to 7.0.16 and 7.1.0 to 7.1.2, the bug is still present
