php.net |  support |  documentation |  report a bug |  advanced search |  search howto |  statistics |  random bug |  login

go to bug id or search bugs for

Bug #75477 last weekday of this month returns previous month when date is set
Submitted: 2017-11-03 10:38 UTC Modified: 2021-04-06 17:25 UTC
From: wouter at deinternetjongens dot nl Assigned:
Status: Not a bug Package: Date/time related
PHP Version: 7.1.11 OS: Linux, mac os
Private report: No CVE-ID: None
View Developer Edit
Welcome back! If you're the original bug submitter, here's where you can edit the bug or add additional notes.
If you forgot your password, you can retrieve your password here.
Password:
Status:
Package:
Bug Type:
Summary:
From: wouter at deinternetjongens dot nl
New email:
PHP Version: OS:

 

 [2017-11-03 10:38 UTC] wouter at deinternetjongens dot nl 
Description:
------------
We came across a `bug` when trying to get the last weekday of a month.
When we first setted a new date and afterwards modified it to get the last weekday of that month it returns the last weekday of the month before the month given.

Test script:
---------------
$datetime = new DateTime()->setDate(2017, 12, 1);
var_dump($datetime->modify('last weekday this month');

Expected result:
----------------
DateTime {#12086
  +"date": "2017-12-30 00:00:00.000000",
  +"timezone_type": 3,
  +"timezone": "UTC",
}

Actual result:
--------------
DateTime {#12086
  +"date": "2017-11-30 00:00:00.000000",
  +"timezone_type": 3,
  +"timezone": "UTC",
}

Patches

Pull Requests

History

AllCommentsChangesGit/SVN commitsRelated reports
 [2017-11-03 10:40 UTC] wouter at deinternetjongens dot nl 
Expected result should be :
----------------
DateTime {#12086
  +"date": "2017-12-29 00:00:00.000000",
  +"timezone_type": 3,
  +"timezone": "UTC",
}
 [2017-11-03 11:15 UTC] sjon at hortensius dot net 
This is also described in the manual: http://php.net/manual/en/datetime.formats.relative.php - so this is basically a feature request.

You could use `last friday of December 2017` instead, see https://3v4l.org/cVpin
 [2017-11-03 11:50 UTC] wouter at deinternetjonges dot nl 
Ok, so this is expected behaviour.

What we are trying to accomplish is getting the last weekday of a month.
So if it is a day between Monday till Friday I want to get the last day of those in a month.

Hope you get where I want to go to with this.
If it still is a feature request how can I ask for something like this to be added ?
 [2017-11-27 20:59 UTC] vandevreken dot hannes at gmail dot com 
Hi!

The only thing it did was:
'last weekday'. Whatever you added next, didn't have much effect (this month doesn't modify it, and is executed first).
Last weekday literally means: going back in time, day by day, till a day has been found which is not a weekend day.

So what you can do is this sequence of modifications:

// Get the very last day in this month.
$datetime->modify('last day of this month');
// Add one day:
$datetime->modify('+1 day')
// Find the last weekday before this day (effectively the first day of next month).
$datetime->modify('last weekday');

Or: but this is very unreadable to anyone coming next:
$datetime->modify(last weekday first day of next month');

This will first go to next month, then get the first day of that month, then find the last weekday before that.
 [2021-04-06 17:25 UTC] derick@php.net
-Status: Open +Status: Not a bug
 [2021-04-06 17:25 UTC] derick@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

This is expected behaviour, and Hannes suggestion is the right workaround.
 
PHP Copyright © 2001-2025 The PHP Group
All rights reserved. 		Last updated: Sat Jul 05 04:01:35 2025 UTC