php check if given date time string has passed, tomorrow, today or other time

function get_timing($time) 
{

    $current_date = date('Y-m-d H:i:s');
    $current_date_day = date('Y-m-d');
    $date_time = strtotime($time);
    $date_time_day = date('Y-m-d', $date_time);
    $date_time_string = date('Y-m-d H:i:s', $date_time);

    if ($date_time_string <= $current_date)
    {
        return 'passed';
    }

    elseif ($date_time_day == $current_date_day)
    {
        return 'today';
    }

    elseif ($date_time_string < date("Y-m-d H:i:s", strtotime("+1 day")))
    {
        return 'tomorrow';
    }

    else
    {
        return 'other';
    }
}