PHP Date and Timezones

[dclamp]

Is there an easy way to make the date function work with the viewer's timezone without having to use mktime?

i know that at some point the user is going to need to give their timezone, but is there a php function that will automatically change it for that session?

[visualAd]

http://uk2.php.net/manual/en/functio...mezone-set.php

You then use getlocaltime

[dclamp]

coming back to this, would setting a time zone plus/minus for each user in the database, then adding/subtracting that time from the unix epoch using date() to format it?

[penagate]

Yes, but why not use the built-in timezone functionality?

(There are even some classes in PHP 5.2 that wrap dates and times, although they didn't work properly the last time I tried.)

[dclamp]

i think i am making a complicated thing out of a simple thing.

I want to have my users select their timezone, should i include all of them, or just some of them..

something that just came to mind is when they are selecing them, they should start typing the name of their city, and i could do like a suggested search type thing...

[dclamp]

hmm found this. will try it.

If you want users to choose their own timezones, here's some code that gets all available timezones but only uses one city for each possible value:

<?php

$timezones = DateTimeZone::listAbbreviations();

$cities = array();
foreach( $timezones as $key => $zones )
{
    foreach( $zones as $id => $zone )
    {
        /**
         * Only get timezones explicitely not part of "Others".
         * @see http://www.php.net/manual/en/timezones.others.php
         */
        if ( preg_match( '/^(America|Antartica|Arctic|Asia|Atlantic|Europe|Indian|Pacific)\//', $zone['timezone_id'] ) )
            $cities[$zone['timezone_id']][] = $key;
    }
}

// For each city, have a comma separated list of all possible timezones for that city.
foreach( $cities as $key => $value )
    $cities[$key] = join( ', ', $value);

// Only keep one city (the first and also most important) for each set of possibilities.
$cities = array_unique( $cities );

// Sort by area/city name.
ksort( $cities );

?>