Converting a user submitted date to GMT

Here is what I came up with.

What do you think?

PHP Code:

function convert_to_utc($date, $time, $tz){

    $standard_timezone = standard_timezone($tz);

    $timestamp =  strtotime("$date $time");

    $system_timezone = new DateTimeZone('UTC'); // your timezone
    $user_timezone = new DateTimeZone($standard_timezone); // your user's timezone
    $now = new DateTime(date('Y-m-d H:i:s',$timestamp), $user_timezone);

    $now->setTimezone($system_timezone);

    $utc_datetime = $now->format('Y-m-d H:i:s');


    return array(
            "user_date"=>$date,
            "user_time"=>$time,
            "utc_full"=>$utc_datetime,
            "utc_date"=>$now->format('Y-m-d'),
            "utc_time"=>$now->format('H:i A'),
            "user_timezone"=>$tz,
            "user_standard_timezone"=>$standard_timezone
        );


} 


PHP Code:

$da = $this->convert_to_utc("07/02/15","9:06 PM","UM5"); 


PHP Code:

Array
(
    [user_date] => 07/02/15
    [user_time] => 9:06 PM
    [utc_full] => 2015-07-03 01:06:00
    [utc_date] => 2015-07-03
    [utc_time] => 01:06 AM
    [user_timezone] => UM5
    [user_standard_timezone] => America/New_York
)