public function __construct($start, $end = null, $timezone = 'UTC')
{
$this->mode = 'month';
$this->timezone = new DateTimeZone($timezone);
$this->today = $this->getTodayDate();
$this->start = new DateTime($start instanceof DateTime ? $start->format('Y-m-d 00:00:00') : $start, $this->timezone);
$this->end = !empty($end) ? new DateTime($end instanceof DateTime ? $end->format('Y-m-d 00:00:00') : $end, $this->timezone) : null;
//Previous period is the previous month started from the the first day of the month
$this->prevInterval = new \DateInterval('P1M');
$this->interval = '1 day';
$this->start = new DateTime($this->start->format('Y-m-01'), $this->timezone);
$this->end = new DateTime($this->start->format('Y-m-t'), $this->timezone);
$this->prevStart = clone $this->start;
$this->prevStart->sub($this->prevInterval);
$this->wholePeriodPerviousEnd = clone $this->prevStart;
$this->wholePeriodPerviousEnd->modify('last day of this month');
$this->determinePrevEnd();
$endoftheday = new \DateInterval('PT23H59M59S');
$this->end->add($endoftheday);
$this->prevEnd->add($endoftheday);
$this->wholePeriodPerviousEnd->add($endoftheday);
if (!$this->di) {
$this->di = \DateInterval::createFromDateString($this->interval);
}
$this->dt = clone $this->start;
}