Only display the month once

Code:

$last_month = '*';

foreach ($results as $result) {

    $date = strtotime($result['event_date']);
    $month = date('M', $date);
    $day = date('d', $date);
    $day_of_week = date('D', $date);

    $section->addText(($month != $last_month ? $month : '')."\t". $day ."\t". $day_of_week ."\t". htmlentities($result['event_title']), null, $event_lists);

    $last_month = $month;
}