docs: def datetimeXPos(self, dtime):
          """
          Returns the x-position for the inputed date time.
          
          :return     <float>
          """
          gantt = self.ganttWidget()
          scale = gantt.timescale()
          
          # calculate the distance for a minute
          if scale == gantt.Timescale.Minute:
              dstart = gantt.dateTimeStart()
              secs = dstart.secsTo(dtime)
              return secs
          
          # calculate the distance for an hour
          elif scale == gantt.Timescale.Hour:
             dstart = gantt.dateTimeStart()
             secs = dstart.secsTo(dtime)
             return secs / 2.0
          
          # calculate the distance for a day
          elif scale == gantt.Timescale.Day:
              dstart = QDateTime(gantt.dateStart(), QTime(0, 0, 0))
              secs = dstart.secsTo(dtime)
              return (secs / (60.0 * 2.0))
          
          # calculate the distance off the date only
          else:
              return self.dateXPos(dtime.date())