Calender types in Python

Question

I have to map a certain number of days, lets say 10590 to a few different calender types, preferrably in python.

The calenders I would like to use are standard, proleptic gregorian, 360 day, 365 day, and 366 day.

I tried looking for such functionality in the python calender module but didn't find anything, at least not a straight forward solution. Does this exist or do i have to implement it myself?

To be clear, I don't need to display anything fancy, just simply map a given day to a date of a given calender type.

Thank you!

Answer 1

Hope this alternative code snippet can help you out. It is using datetime instead. Tested locally:

import datetime

class Calendar:
    def __init__(self, start_year, start_month, start_day):
        self.start_date = datetime.date(start_year, start_month, start_day)

    def days_to_date(self, days):
        raise NotImplementedError


class GregorianCalendar(Calendar):
    def __init__(self):
        super().__init__(1900, 1, 1)

    def days_to_date(self, days):
        return self.start_date + datetime.timedelta(days=days)


class ProlepticGregorianCalendar(Calendar):
    def __init__(self):
        super().__init__(1, 1, 1)

    def days_to_date(self, days):
        return self.start_date + datetime.timedelta(days=days)


class ThreeSixtyDayCalendar(Calendar):
    def __init__(self):
        super().__init__(1900, 1, 1)

    def days_to_date(self, days):
        years, days_in_year = divmod(days, 360)
        target_year = self.start_date.year + years
        target_month, target_day = divmod(days_in_year, 30)
        return datetime.date(target_year, target_month + 1, target_day + 1)


class ThreeSixtyFiveDayCalendar(Calendar):
    def __init__(self):
        super().__init__(1, 1, 1)

    def days_to_date(self, days):
        return self.start_date + datetime.timedelta(days=days - 1)


class ThreeSixtySixDayCalendar(Calendar):
    def __init__(self):
        super().__init__(1, 1, 1)

    def days_to_date(self, days):
        return self.start_date + datetime.timedelta(days=days - 1)


class CalendarFactory:
    @staticmethod
    def create_calendar(calendar_type):
        if calendar_type == 'gregorian':
            return GregorianCalendar()
        elif calendar_type == 'proleptic_gregorian':
            return ProlepticGregorianCalendar()
        elif calendar_type == '360_day':
            return ThreeSixtyDayCalendar()
        elif calendar_type == '365_day':
            return ThreeSixtyFiveDayCalendar()
        elif calendar_type == '366_day':
            return ThreeSixtySixDayCalendar()
        else:
            raise ValueError('Invalid calendar type')


days = 10590

# create Gregorian calendar and map days to date
calendar = CalendarFactory.create_calendar('gregorian')
print(calendar.days_to_date(days))  # prints: 1931-06-26

# create 360-day calendar and map days to date
calendar = CalendarFactory.create_calendar('360_day')
print(calendar.days_to_date(days))  # prints: 1930-10-29