/**
* Get the time period based on the $time timestamp and the Time Step
* defined. If $time is skipped or set to null the current timestamp will
* be used.
*
* @param int|null $time Timestamp
*
* @return integer The time period since the UNIX Epoch
*/
public function getPeriod($time = null)
{
if (\is_null($time)) {
$time = time();
}
$period = floor($time / $this->_timeStep);
return $period;
}