source/php/App.php
public static function formatEventDate($start_date, $end_date)
    {
        $start = date('Y-m-d H:i:s', strtotime($start_date));
        $end = date('Y-m-d H:i:s', strtotime($end_date));
        $date = mysql2date('j F Y, H:i', $start, true) . ' ' . __('to', 'event-integration') . ' ' . mysql2date('j F Y, H:i', $end, true);
        if (date('Y-m-d', strtotime($start)) == date('Y-m-d', strtotime($end))) {
            $date = mysql2date('j F Y, H:i', $start, true) . ' - ' . mysql2date('H:i', $end, true);
        }

        return $date;
    }
public static function formatEventDate($start_date, $end_date)
    {
        $start = date('Y-m-d H:i:s', strtotime($start_date));
        $end = date('Y-m-d H:i:s', strtotime($end_date));
        $date = mysql2date('j F Y, H:i', $start, true) . ' ' . __('to', 'event-integration') . ' ' . mysql2date('j F Y, H:i', $end, true);
        if (date('Y-m-d', strtotime($start)) == date('Y-m-d', strtotime($end))) {
            $date = mysql2date('j F Y, H:i', $start, true) . ' - ' . mysql2date('H:i', $end, true);
        }

        return $date;
    }
Format start and end date
@param  string $start_date occasion start date
@param  string $end_date   occasion end date
@return string             formatted date