time differences

[liamoco]

I am making a php/ajax chat, when a post is sent to the chat, a timestamp using mktime() is stored in the database to show when that post was sent. My concern is that I am from England and my timestamp is GMT +0. Will people from different locations around the world see the wrong times that other users post into the chat? If so what do I need to do to make this work ideally?

 

Thanks

[litebearer]

random thought, (sure there is a better way) presuming users are registered users...

1. store the time as GMT time

2. have field in db that holds the offset for a user from GMT

3. when user logs in, get his/her offset and use that combined with the stored GMT to display dates/times in users local time.

 

ie user 1 in UK - offset 0 - when user 1 sees a record with 11AM as stored value he/she see 11AM; whereas a user in CA USA would have offset of -8 and as such would see same record as 3AM

 

is that somewhat what you are seeking?

[liamoco]

Yes thank you litebearer, how to I get the offset value for a user?

[johnny86]

What about using PHPs DateTime object with DateTimeZone object?

<?php
$timezone = new DateTimeZone("Europe/London");
$date = new DateTime(null, $timezone);

// OR just

$date = new DateTime(null, new DateTimeZone("Europe/London");

// Either way $date will now produce times according to given timezone
?>

 

Read more:

http://www.php.net/manual/en/class.datetime.php

http://www.php.net/manual/en/class.datetimezone.php