PHP Create Timeslots with break timing using DatePeriod

I want to create time slots with start,end time & also break timing.

public function getServiceScheduleSlots($duration,$break, $stTime,$enTime)
{
    $start = new DateTime($stTime);
    $end = new DateTime($enTime);
    $interval = new DateInterval("PT" . $duration. "M");
    $period = new DatePeriod($start, $duration, $end);

    foreach ($period as $dt) {
        $periods[] = $dt->format('H:iA');
    }
    return $periods;
}

For ex.,
My service start time 10:00 AM , End Time 12:00 PM.
Condition: each service time 30 min & 15 min break.

Above method returns like,

• 10:00 AM - 10:30 AM
• 10:30 AM - 11:00 AM
• 11:00 AM - 11:30 AM
• 11:30 AM - 12:00 PM

Expected results as,

• 10:00 AM - 10:30 AM
• 10:45 AM - 11:15 AM
• 11:30 AM - 12:00 PM

I want to add break time when each period starts.

Thanks in advance.