docs: def daytime(date: datetime.date,
                  daybreak: datetime.time = datetime.time(NORMAL_DAY_START_H),
                  nightfall: datetime.time = datetime.time(NORMAL_DAY_END_H)) \
              -> "Interval":
          """
          Returns an :class:`Interval` representing daytime on the date given.
          """
          return Interval(
              datetime.datetime.combine(date, daybreak),
              datetime.datetime.combine(date, nightfall),
          )