TimeHelper::getSecondsFromDateTime

public function getSecondsFromDateTime($dateTime)
{
	$parts = explode(':', $dateTime->format('G:i:s'));
	return (int)$parts[0] * TimeDictionary::SECONDS_PER_HOUR
		   + (int)$parts[1] * TimeDictionary::SECONDS_PER_MINUTE
		   + (int)$parts[2];
}