/**
  * Gets start date.
  * @param string $dateRangeType
  * @return string
  */
 public static function getStartDate($dateRangeType)
 {
     assert('is_string($dateRangeType)');
     if ($dateRangeType == SavedCalendar::DATERANGE_TYPE_MONTH) {
         return DateTimeUtil::getFirstDayOfAMonthDate();
     }
     if ($dateRangeType == SavedCalendar::DATERANGE_TYPE_WEEK) {
         return DateTimeUtil::getFirstDayOfAWeek();
     }
     if ($dateRangeType == SavedCalendar::DATERANGE_TYPE_DAY) {
         return DateTimeUtil::getTodaysDate();
     }
 }