Calculating start and end dates of a week.

Wednesday, September 6th 2006, 09:25 CEST

Skien, Norway

A friend asked "How do I calculate start (monday) and end (sunday) dates from a given week number for a specified year?" Instead of having to come up with your own algorithm you can simply do the following in PHP 5.1 and higher:

<?php
// Monday
echo date(
    datetime::ISO8601,
    strtotime("2006W37"));

// Sunday
echo date(
    datetime::ISO8601,
    strtotime("2006W377"));
?>

The format is " year 'W' weeknr ( daynr )?" where the default daynr is 1 being the Monday of that week. The daynr can be in the range 0 to 7. The weeknr is the ISO week number . Please note that the " year '-W' weeknr ( '-' daynr )?" format is only supported in PHP 5.2 and higher.

Shortlink

This article has a short URL available: https://drck.me/csaedoaw-4wr

Comments

Paulg

Wednesday, September 6th 2006, 13:20 UTC

Thanks Derek, that is going to make life a lot easier!

Toni

Thursday, September 7th 2006, 01:50 UTC

Keep it simple and just do strtotime('-1 Sunday',$currentDay);

it is simpler and uses less resources.

Ammar Ibrahim

Thursday, September 7th 2006, 09:38 UTC

or you could use PEAR::Date(), it makes it very easy as well

Derick

Thursday, September 7th 2006, 11:54 UTC

@Ammar: Why would you want to use a wrapper class in PHP when the extension supports it?

Pabblo

Sunday, June 29th 2008, 03:18 UTC

Hey Dereck

thanks for confirming yet again why I love the Internet... I've been playing around with this particular problem for the last few days... any solution I had was not nearly as elegant and simple as this... glad I found this posting...will help tremendously.

Paul

Wednesday, July 23rd 2008, 06:42 UTC

echo date("Y-m-d", strtotime(date("Y").'W'.date('W')."7"));

Jackson

Monday, June 22nd 2009, 22:09 UTC

If 1 for daynr represents monday, what does 0 represent? How can it accept values 0-7?

Bjorn

Tuesday, October 13th 2009, 14:20 UTC

Thnx! Just what I was looking for!

Mamoon Rashid

Monday, May 24th 2010, 18:10 UTC

Thank you very much!

Nate Dawg

Friday, June 18th 2010, 00:03 UTC

Excellent example of exactly what a lot of people need. Please keep this example up for the rest of the PHP newbs like me!

Undercrumble

Friday, January 21st 2011, 16:22 UTC

You have just saved me a lot of time on deadline day at work.

Thanks!

Steffen

Tuesday, March 1st 2011, 18:13 UTC

Thank you very much. This threat was my first search result: "php calculate start end week"..

Alexander Wallin

Tuesday, June 7th 2011, 13:30 UTC

Wow. I had no clue about this. Thanks, man!

Leslie

Wednesday, April 4th 2012, 15:03 UTC

Very very usefull, I knew about the W weeks implemented in recent php but this is pretty useful, saved me on a thing I have to do at work :)

Ahsan

Friday, April 20th 2012, 10:15 UTC

Excellent...!

Exactly what I was looking for.

Monday, February 4th 2013, 15:12 UTC

Even in 2013 this is very useful, thanks! Saved me much work

Brittny Hansen

Wednesday, March 13th 2013, 22:54 UTC

Thank you! I was getting very frustrated trying to get my dates to format properly, you're a lifesaver!

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