maths.zellers_congruence
========================

.. py:module:: maths.zellers_congruence


Attributes
----------

.. autoapisummary::

   maths.zellers_congruence.parser


Functions
---------

.. autoapisummary::

   maths.zellers_congruence.zeller


Module Contents
---------------

.. py:function:: zeller(date_input: str) -> str

   | Zellers Congruence Algorithm
   | Find the day of the week for nearly any Gregorian or Julian calendar date

   >>> zeller('01-31-2010')
   'Your date 01-31-2010, is a Sunday!'

   Validate out of range month:

   >>> zeller('13-31-2010')
   Traceback (most recent call last):
       ...
   ValueError: Month must be between 1 - 12
   >>> zeller('.2-31-2010')
   Traceback (most recent call last):
       ...
   ValueError: invalid literal for int() with base 10: '.2'

   Validate out of range date:

   >>> zeller('01-33-2010')
   Traceback (most recent call last):
       ...
   ValueError: Date must be between 1 - 31
   >>> zeller('01-.4-2010')
   Traceback (most recent call last):
       ...
   ValueError: invalid literal for int() with base 10: '.4'

   Validate second separator:

   >>> zeller('01-31*2010')
   Traceback (most recent call last):
       ...
   ValueError: Date separator must be '-' or '/'

   Validate first separator:

   >>> zeller('01^31-2010')
   Traceback (most recent call last):
       ...
   ValueError: Date separator must be '-' or '/'

   Validate out of range year:

   >>> zeller('01-31-8999')
   Traceback (most recent call last):
       ...
   ValueError: Year out of range. There has to be some sort of limit...right?

   Test null input:

   >>> zeller()
   Traceback (most recent call last):
       ...
   TypeError: zeller() missing 1 required positional argument: 'date_input'

   Test length of `date_input`:

   >>> zeller('')
   Traceback (most recent call last):
       ...
   ValueError: Must be 10 characters long
   >>> zeller('01-31-19082939')
   Traceback (most recent call last):
       ...
   ValueError: Must be 10 characters long


.. py:data:: parser