Edit report at https://bugs.php.net/bug.php?id=62193&edit=1

 ID:                 62193
 Updated by:         ras...@php.net
 Reported by:        thomasrothwell dot 1990 at gmail dot com
 Summary:            strtotime returning wrong month
 Status:             Not a bug
 Type:               Bug
 Package:            Date/time related
 Operating System:   Ubuntu 12.04 LTS & Ubuntu 10.04
 PHP Version:        5.3Git-2012-05-31 (Git)
 Block user comment: N
 Private report:     N

 New Comment:

This is standard UNIX behaviour. You need to be explicit as you discovered. Try 
the same thing in a shell script, for example:

$ date
Fri May 31 16:37:45 PDT 2013
$ date --date='+1 month' +'Next month is %B'
Next month is July

SQLite and many other tools you will come across follow this same standard 
behaviour when it comes to data manipulation. It is described by GNU here:

http://www.gnu.org/software/tar/manual/html_node/Relative-items-in-date-
strings.html#SEC120

There is really no good answer to this one. We can't just assume the 1st of the 
month, because then adding 1 day would be equivalent to adding 1 month on the 
last day of the month. That's a huge amount of data loss. So we follow the 
UNIX/GNU convention.


Previous Comments:
------------------------------------------------------------------------
[2013-05-31 19:37:22] phpbugs at thehiltons dot net

How this is an overflow issue:

$timeStr =  strtotime('Jun'); // just 'Jun'
$date = getdate($timeStr);

The date represented by $date should be in June, but it's not.
Since I didn't specify a day it shouldn't be an overflow issue.
If the day is assumed/implied by the current day then that should be documented.
I would argue that since it is not specified, the 1st of the month at 0:00:00 
is 
the safest assumption.

------------------------------------------------------------------------
[2013-05-31 18:10:57] ahar...@php.net

Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to report
a bug at http://bugs.php.net/how-to-report.php

PHP date functions will overflow out of bound values: since June 31 doesn't 
exist, it becomes July 1.

------------------------------------------------------------------------
[2013-05-31 15:29:50] phpbugs at theHiltons dot net

Reproduced May 31st, 2013, CentOS 64Bit, PHP 5.4.15:
foreach (['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 
'Nov', 'Dec'] as $monthName) {
    echo "getdate(strtotime('$monthName'))['month'] = " . 
getdate(strtotime($monthName))['month'] . "\n";
    echo "getdate(strtotime('$monthName'))['mon'] = " . 
getdate(strtotime($monthName))['mon'] . "\n";
}

------------------------------------------------------------------------
[2012-05-31 02:25:24] thomasrothwell dot 1990 at gmail dot com

Assuming the issue is related to June only having 30 days, which then pushes it 
to the next month July.

<?php
  2 //Expected 30/06
  3 echo date('d/m', strtotime('+1 MONTH'));
  4 //Result 01/07
  5 
  6 //Expected 30/06
  7 echo gmdate('d/m', strtotime('+1 MONTH'));
  8 //Result 01/07
  9 
 10 //Expected 01/06
 11 echo date('d/m', strtotime('first day of +1 month'));
 12 //Result 01/06


Could be safe to assume that the function should check the limits of each month 
to prevent it from going past the extreme.

------------------------------------------------------------------------
[2012-05-31 02:10:51] thomasrothwell dot 1990 at gmail dot com

Description:
------------
Came across the wrong month being returned when using the following:
<?php echo date('m', strtotime('+1 MONTH')); ?>
Expected: 06
Result: 07

I've only noticed this occur Today (31st of May 2012).

Altered my php.ini to use the following config as well:

date.timezone = "Australia/Sydney"
date.default_latitude = -35.308142
date.default_longitude = 149.124518

Thinking it could be a timezone issue. Also attempted use of gmdate.

What I found to work was:
<?php echo date('m', strtotime('first day of +1 month')); ?>
Expected: 06
Result: 06


Test script:
---------------
<?php
//Expected 06
echo date('m', strtotime('+1 MONTH'));
//Result 07

//Expected 06
echo gmdate('m', strtotime('+1 MONTH'));
//Result 07

//Expected 06
echo date('m', strtotime('first day of +1 month'));
//Result 06

Expected result:
----------------
060606

Actual result:
--------------
070706


------------------------------------------------------------------------



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