How can I simply change the Timezone Offset with Zend_Date?

Question

I'm using Zend_Date to manage dates/times in a scheduling app.

The only way I'm able to determine the user's Timezone is via Javascript which only gives a Timezone Offset. Zend_Date only seems to take Timezones in the 'America/New_York' format.

Is there a way to get the users timezone in this format or set the Timezone Offset with Zend_Date?

Thanks!

Answer 1

You can use javascript to set a cookie to the users timezone offset.

Then in php you can have an array indexed by offset

$timezones = array (

    '-1' => 'adfas/adsfafsd',
    '-2' => 'adsfasdf/asdfasdf'
    ...
);

$date->setTimezone( $timezones[$_COOKIE['tz_offset']] );

Answer 2

Nicky,

You don't really need Zend_Date for this as the PHP intrinsic DateTime and DateTimeZone objects work well for this; however, I can point you in the right direction if you really need to use Zend_Date.

See the following examples

1. $date = new Zend_Date(1234567890, false, $locale);
2. $date->toString... (see: http://framework.zend.com/manual/en/zend.date.constants.html for more details)
3. Use the following Constants for ISO 8601: (Z = Difference of time zone [+0100])

This should get you to where you need to be. Please post code samples if you get stuck.

Answer 3

You could use the timezone_name_from_abbr function:

$javascript_offset = '-1';
$zone = timezone_name_from_abbr('', $javascript_offset * 3600, 0);

You will also need to consider DST. Have a look at this example for more info.