Implementation of Zeller's congruence to determine the day of the week given the date
This program uses the formula for Zeller's congruence to determine the day of the week (Sunday, Monday, ...) based on a date (ex: "July 4, 1776") in either the Gregorian and Julian calendars.
make && sudo make installzeller [-j] "Month Day, Year"Use the -j flag to return the day of the week in the Julian calendar. Results are Gregorian by default.