wrong “past-event” class

I’m using My Calendar 2.5.6 and found that the future event container tag sometimes has “past-event” class.

I investigate the code and found that mc_event_classes() function in my-calendar-output.php adds class names.

$ts  = $event->ts_occur_begin;
$end = $event->ts_occur_end;
$now = current_time( 'timestamp' );
if ( $ts < $now && $end > $now ) {
    $date_relation = 'on-now';
} else if ( $now < $ts ) {
    $date_relation = 'future-event';
} else if ( $now > $ts ) {
    $date_relation = 'past-event';
}

I think $event->ts_occur_begin and $event->ts_occur_end are GMT, but current_time('timestamp') returns local time, so it should be current_time('timestamp', 1).