docs: def _set_period(self, period):
  		"""
  		Set the period for the timestamp.  If period is 0 or None, no period
  		will be used.
  		"""
  		self._period = period
  		if period:
  			self._period_seconds = tempora.get_period_seconds(self._period)
  			self._date_format = tempora.get_date_format_string(
  				self._period_seconds)
  		else:
  			self._period_seconds = 0
  			self._date_format = ''