Zeller's Algorithm

This algorithm can tell you what day of the week a given day was. Just select the date, including the year and click calculate.
Zeller's Algorithm Implementation

This is a date calculator utilising Zeller's Algorithm, an algorithm that I learnt whilst doing A-level maths, it is rather complex, and looking at it a few years after I completed it, it is quite a poor example of programming. It did however teach me a lot about using arrays and is an extremely useful example for general programming techniques (apart from of course commenting and indenting code)