code: def _adjust_datetime(self, sampfrom):
          
          if sampfrom:
              dt_seconds = sampfrom / self.fs
              if self.base_date and self.base_time:
                  self.base_datetime = datetime.datetime.combine(self.base_date,
                                                                 self.base_time)
                  self.base_datetime += datetime.timedelta(seconds=dt_seconds)
                  self.base_date = self.base_datetime.date()
                  self.base_time = self.base_datetime.time()
              # We can calculate the time even if there is no date
              elif self.base_time:
                  tmp_datetime = datetime.datetime.combine(
                      datetime.datetime.today().date(), self.base_time)
                  self.base_time = (tmp_datetime
                                    + datetime.timedelta(seconds=dt_seconds)).time()
docs: Adjust date and time fields to reflect user input if possible.
  
          Helper function for the `_arrange_fields` of both Record and
          MultiRecord objects.