docs: def setDateStart( self, dateStart ):
          """
          Sets the start date for this item.  This will automatically push the
          end date to match the duration for this item.  So if the item starts
          on 1/1/12 and ends on 1/2/12, and the start date is changed to 2/1/12,
          the end date will change to 2/2/12.  To affect the duration of the 
          item, use either setDuration, or setDateEnd.
          
          :param      dateStart | <QDate>
          """
          dateStart = QDate(dateStart)
          
          duration = self.duration()
          self._dateStart = dateStart
          self._dateEnd   = dateStart.addDays(duration - 1)
          self.markForRebuild()