Contao\Date::createDateRanges PHP Method

    protected function createDateRanges()
    {
        if (!empty($this->arrRange)) {
            return;
        }
        $intYear = date('Y', $this->strDate);
        $intMonth = date('m', $this->strDate);
        $intDay = date('d', $this->strDate);
        $this->arrRange['day']['begin'] = mktime(0, 0, 0, $intMonth, $intDay, $intYear);
        $this->arrRange['day']['end'] = mktime(23, 59, 59, $intMonth, $intDay, $intYear);
        $this->arrRange['month']['begin'] = mktime(0, 0, 0, $intMonth, 1, $intYear);
        $this->arrRange['month']['end'] = mktime(23, 59, 59, $intMonth, date('t', $this->strDate), $intYear);
        $this->arrRange['year']['begin'] = mktime(0, 0, 0, 1, 1, $intYear);
        $this->arrRange['year']['end'] = mktime(23, 59, 59, 12, 31, $intYear);
    }