How to check is timezone identifier valid from code?

Question

I\'ll try to explain what\'s the problem here.

According to list of supported timezones from PHP manual, I can see all valid TZ identifiers in PHP.

My first

Answer 1

In case of php<5.3, how about this?

public static function is_valid_timezone($timezone)
{
    $now_timezone = @date_default_timezone_get();

    $result = @date_default_timezone_set($timezone);

    if( $now_timezone ){    
        // set back to current timezone
        date_default_timezone_set($now_timezone);
    }

    return $result;
}