# An Extended Approach to the Julian and the Gregorian calendar

Welcome!
Calculating the day of the week is now simple.
I have written an article titled "An Extended Approach to The Julian and The Gregorian Calendar" which was published in The Mathematical Gazette, London in November 2004. Here, I have tried to explain the concepts given in the above article in detailed but lucid manner.
Many students, teachers and experts have visited and benefitted from this article. People who have used the below mentioned weekday formula and/or the algorithm in different programming languages have called it (for identification) 'Babwani's Method' or 'Babwani's Formula' or 'Babwani's Congruence' or 'Babwani's Algorithm'. You may call it by any name. But to maintain uniformity and identification, the same formulae are collectively referred as 'Babwani's Congruence' and steps to find out the years and the algorithms in general as 'Babwani's Algorithm'.
You need to refer the explanatory document wherein the concepts given in the Babwani's Congruence have been explained methodically.
Secondly, a program Calember (Calendar + Number), that calculates the weekday, dates, months and years based on the explanations given in the document, has been prepared and made available.
Remember, this is not the first time such a formula is made. Many formulae existed even before I invented this method. But this is the first time, you will discover a different approach to find weekdays, dates, months and even years when other data is provided. What's more special is the flexibility of methods that are at your disposal as it also explains alternative easy ways of doing the same calculations. It also presents algorithms that can be used to prepare your own program.
Thus you can find out the weekdays, dates, months and years by either by:
1) Pen and a paper and one of the formulae. (Also see the FAQ page)
2) Orally. (Depends on your mental ability and practice)
3) Using a computer program.
4) Calendar Slider. (See Calendar Slider page for more details)