code: def get_period_strs(self, now=None):
          
          if now is None:
              now = self.dt.utcnow()
  
          year_str = "%04d" % now.year
          month_str = "%04d-%02d" % (now.year, now.month)
          day_str = "%04d-%02d-%02d" % (now.year, now.month, now.day)
          hour_str = "%04d-%02d-%02dT%02d" % (
              now.year, now.month, now.day, now.hour)
  
          # Note: The week number may be in the previous year during the last
          # days of the year.
          isocal = now.isocalendar()
          week_str = "%04d-W%02d" % (isocal[0], isocal[1])
  
          return {
              "year": year_str,
              "month": month_str,
              "day": day_str,
              "hour": hour_str,
              "week": week_str,
          }
docs: meterer.get_period_strings()
  
          Return the period strings for the specified time (defaulting to the
          current time if not specified).