code: def shift_dateint(dateint, day_shift):
      
      dtime = dateint_to_datetime(dateint)
      delta = timedelta(days=abs(day_shift))
      if day_shift > 0:
          dtime = dtime + delta
      else:
          dtime = dtime - delta
      return datetime_to_dateint(dtime)
docs: Shifts the given dateint by the given amount of days.
  
      Arguments
      ---------
      dateint : int
          An integer object decipting a specific calendaric day; e.g. 20161225.
      days : int
          The number of days to shift the given dateint by. A negative number
          shifts the dateint backwards.
  
      Returns
      -------
      int
         A dateint corresponding to the given date shifted by the given amount
         of days.
  
      Example
      -------
      >>> shift_dateint(20170228, 1)
      20170301
      >>> shift_dateint(20170301, -1)
      20170228
      >>> shift_dateint(20170220, 5)
      20170225