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

Why not use @ operator? This code works pretty well, and you don't change default timezone:

function isValidTimezoneId($timezoneId) {
    @$tz=timezone_open($timezoneId);
    return $tz!==FALSE;
}

If you don't want @, you can do:

function isValidTimezoneId($timezoneId) {
    try{
        new DateTimeZone($timezoneId);
    }catch(Exception $e){
        return FALSE;
    }
    return TRUE;
}