Comments on: Calculating Daylight Savings Time Boundary In PHP

By: Mike Jourard

Mike Jourard — Mon, 24 Oct 2011 15:10:16 +0000

Thanks for the tip! This is really helpful for one of my programms. I have a newsletter that pulls events for the next four weeks out of a calendar system. The system stores the event timestamps as GMT/UTC, but we are in either EST or EDT. If the current newsletter straddles the time change, the times for events after the time change are shown an hour off! By checking the event date against the time change boundary calculation, I can compensate for the discrepancy.

By: Jim Linder

Jim Linder — Thu, 13 Oct 2011 23:24:36 +0000

Not sure if it is the best way to do what I need, but I used this to determine how many hours to offset the server time for the apps I am building, so the user sees local time. It worked like a charm, thanks.

By: David

David — Wed, 22 Jun 2011 06:02:38 +0000

Bro, many thanks! This was a lifesaver.

By: Minway Hsu

Minway Hsu — Thu, 31 Mar 2011 22:39:28 +0000

It’s helpful.Thanks a lot!

By: Matt

Matt — Thu, 27 Jan 2011 01:37:31 +0000

@volomike: it depends on the underlying date/time libs that PHP uses. On most Linux distros, they’re using the standard tzdata tables, which have all worldwide time zone and DST rules, and are updated frequently to keep pace with countries changing their DST rules.

By: haris

haris — Thu, 02 Sep 2010 05:50:05 +0000

nice post, it helped me a lot

By: Jesse

Jesse — Fri, 11 Sep 2009 12:50:39 +0000

Thanks for this script. The php docs just weren’t clear enough for me, plus Yahoo! hasn’t upgraded to php 5 yet, so this is an awesome hack around.

By: volomike

volomike — Sun, 26 Apr 2009 03:25:30 +0000

Does your code work for non-USA timezones like in the UK?

By: Daniel Cousineau’s Blog: Calculating Daylight Savings Time Boundary In PHP : Dragonfly Networks

Thu, 12 Mar 2009 04:52:25 +0000

[...] Cousineau has written up some timely advice in a new post to his blog. It looks at pinpointing the time boundary for Daylight Savings Time in a PHP script [...]

By: Daniel Cousineau

Daniel Cousineau — Tue, 10 Mar 2009 17:14:50 +0000

The system I was working on was importing the timestamps and the DST information wasn’t being applied correctly.

My solution may be a temporary hack but it was a fun exercise playing with strtotime() and realizing how good I have it with PHP’s date functions.