old_contents: from datetime import date
  
  from base import Calendar
  from date import InvalidDate
  from main import JulianCalendar
  
  class JulianToGregorianCalendar(Calendar):
      def date(self, year, month, day):
          gregorian_date = date(year, month, day)
          if gregorian_date < self.first_gregorian_day:
              julian_date = JulianCalendar().date(year, month, day)
              if julian_date > self.first_gregorian_day:
                  raise InvalidDate("This is a 'missing day' when the calendars changed.")
              self.bless(julian_date)
              return julian_date
          return self.from_date(gregorian_date)
  
      def bless(self, date):
          date.calendar = self.__class__
  
  class EnglishHistoricalCalendar(JulianToGregorianCalendar):
      first_gregorian_day = date(1752, 9, 13)
  
new_contents: from datetime import date
  
  from base import Calendar
  from date import InvalidDate
  from main import JulianCalendar
  
  class JulianToGregorianCalendar(Calendar):
      def date(self, year, month, day):
          gregorian_date = date(year, month, day)
          if gregorian_date < self.first_gregorian_day:
              julian_date = JulianCalendar().date(year, month, day)
              if not julian_date < self.first_gregorian_day:
                  raise InvalidDate("This is a 'missing day' when the calendars changed.")
              self.bless(julian_date)
              return julian_date
          return self.from_date(gregorian_date)
  
      def bless(self, date):
          date.calendar = self.__class__
  
  class EnglishHistoricalCalendar(JulianToGregorianCalendar):
      first_gregorian_day = date(1752, 9, 13)
  
subject: Change comparison to be non-strict.