Solved

PHP/MySQL timezones screwing up

Posted on 2011-03-18
5
457 Views
Last Modified: 2012-05-11
OK,

I have a problem. I'm setting up a sight that will end up holding large amounts of client data records. Because the clients can export and import their data, i have to be able to maintain session based timezones with in the site and server.

Right now my server is set to GMT. When i run the date command on the shell i see, which is correct at time of posting.

    Fri Mar 18 20:04:32 GMT 2011

Then when i do hwclock --show is gives me, again this is was correct.

    Fri 18 Mar 2011 08:06:22 PM GMT

Now when i tell php to change it's timezone to GMT-4 (since that is my timezone factoring in DST)

    date_default_timezone_set('Etc/GMT-4');
    echo date("m/d/Y g:i:s A T");

I get 03/19/2011 00:11:35 AM GMT-5 Is is totally wrong in stead of taking 5 hours away it added 5 hours.

So then I did this:

    date_default_timezone_set('Etc/GMT+4');
    echo date("m/d/Y g:i:s A T");

I got 03/18/2011 4:14:56 PM GMT+4. Which is the correct time. MySQL does the same thing. It seems like both are wanting to invert the time adjustments. Am i missing something on the settings?

0
Comment
Question by:Pyromanci
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 2
  • 2
5 Comments
 
LVL 6

Expert Comment

by:ramelong
ID: 35169815
You may try this in order to determinate if anything else is wrong:
<?
ini_set('display_errors', 1);
error_reporting(E_ALL);
echo date("m/d/Y g:i:s A T");
?>

Open in new window

since some notices and warnings of time issues related are hidden in default error reporting configuration.

Additionally, accepted time zones are listed in http://ar.php.net/manual/en/timezones.php
0
 
LVL 5

Author Comment

by:Pyromanci
ID: 35173083
There are no errors reported.
0
 
LVL 110

Expert Comment

by:Ray Paseur
ID: 35173600
This article is kind of lengthy, but it will answer your questions about time and localization.
http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/PHP/A_201-Handling-date-and-time-in-PHP-and-MySQL.html

Please read it over and then post back with a code sample showing the issue, if you still have questions.

best regards, ~Ray
0
 
LVL 5

Author Comment

by:Pyromanci
ID: 35201335
That post didn't really give me that much information that i did not know. Nor does it cover why when i tell it -5 it adds 5 and when tell it +5 it minus's 5
0
 
LVL 110

Accepted Solution

by:
Ray Paseur earned 500 total points
ID: 35202162
Please see the large red warning on the man page here, and see the comments in the User-Contributed notes:
http://php.net/manual/en/timezones.others.php

A line of code that says this explicitly defies the warning, and ignores the notes.  
date_default_timezone_set('Etc/GMT+4');

Don't do that.  Instead use one of the recommended Time Zone names.

Let me try this again... and then post back with a code sample showing the issue.  Thanks. ~Ray
0

Featured Post

Secure Your WordPress Site: 5 Essential Approaches

WordPress is the web's most popular CMS, but its dominance also makes it a target for attackers. Our eBook will show you how to:

Prevent costly exploits of core and plugin vulnerabilities
Repel automated attacks
Lock down your dashboard, secure your code, and protect your users

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Load balancing is the method of dividing the total amount of work performed by one computer between two or more computers. Its aim is to get more work done in the same amount of time, ensuring that all the users get served faster.
Many old projects have bad code, but the budget doesn't exist to rewrite the codebase. You can update this code to be safer by introducing contemporary input validation, sanitation, and safer database queries.
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…
This tutorial will teach you the core code needed to finalize the addition of a watermark to your image. The viewer will use a small PHP class to learn and create a watermark.

696 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question