Time difference in PHP using timezone function?

Question

I am trying to find a way to display a difference in time between two locations using timezone function in PHP: http://php.net/manual/en/timezones.php

lets say I have ch

Answer 1

function get_timezone_offset( $origin_tz, $remote_tz ) {
    $timezone1 = new DateTimeZone( $origin_tz );
    $timezone2 = new DateTimeZone( $remote_tz );

    $datetime1 = new DateTime("now", $timezone1);
    $datetime2 = new DateTime("now", $timezone2);

    $offset = $timezone1->getOffset($datetime1) - $timezone2->getOffset($datetime2);
    return $offset;
}

$offset = get_timezone_offset( 'Europe/London', 'Asia/Shanghai' );

// convert offset to hours
echo $offset/3600;