weekday_zeller, a Python code which uses Zeller's congruence to determine the day of the week corresponding to a given date, such as 13 July 1989, Gregorian calendar, ... which was a Thursday.
The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.
weekday_zeller is available in a MATLAB version and a Python version.
calpak, a Python code which makes various calendar calculations;
dates, a dataset directory which contains lists of dates in various calendar systems.
doomsday, a Python code which is given the year, month and day of a date, and uses John Conway's doomsday algorithm to determine the corresponding day of the week.
weekday, a Python code which determines the day of the week for a given day.