Time Questions (PHP)

[catacon]

*Sigh*

I have been working on my website a lot lately and I have added somethings that have a timestamp on them (like a post in a forum). I want the members to be able to select which timezone they are in, and then have the script change the timestamp accordingly. So if I post at 3:00 PM (GMT -6) then in GMT -5 it would be 4:00 PM. How do take a date from a db and change it to the correct timezone depending on what the user has set?

Also, how would I set Daylight Savings Time? Like in this forum, you can select if you want DST, on, off, or automatically changed.

Any help would be much appreciated.

[mairving]

Be pretty easy to do. Just create a separate column in the database like time offset. You could then just subtract the value to give them their time.

DST would be more complicated. I would have to think on that one. You might download PHPBB and look at how they do some of their date calculations.

[catacon]

I would have to set the time to GMT first, before I add/substract the offset, right? I will get PHPBB and see what they do. Thanks!

[catacon]

PHPBB confused me, oh well. I am having a problem with taking time from the database.

Very simply, here is what I am doing.

PHP Code:


<?php


require_once ("includes/mysql_connect.php"); //connects to db

// Query only selects date/time, nothing else for now

$query = "SELECT DATE_FORMAT(date_entered, '%M %d, %Y') AS de, HOUR(time_entered, '%H') AS he, MINUTE(time_entered, '%i') AS me FROM db LIMIT 5";

$result = @mysql_query($query);

if ($result) {

   $row = mysql_fetch_array ($result);

   $hour = date ( 'g', $row['he'] );
   $GMT = $hour + 6; 
   $new_hour = $GMT + $_SESSION['time_offset'];
   $minute = date ( 'i', $row['me'] );
   $ampm = date ( 'A', $row['he'] );

   echo $new_hour:minute . " on " . $row['de'];

} else {
     echo mysql_error();
}

?>

The problem occurs when adding the time offset makes the time go into the next day. If I enter the Central 6:00PM that becomes GMT 12:00PM (noon, wrong) and then add the time_offset of 9 (for example) then it becomes 9:00PM the same day. It should be 7:00AM the following day (right?). And it prints it out as 21:00 PM too. Any help would be appreciated.

I am also still having trouble figuring out how to use DST.

Any typos in the code aren't in the code I am using, I just wrote this up fast to show what I was doing.

Thank you!