First I began with one year calendars in the following way: -

The above table can be called as a perfect infinite year calendar that can calculate the weekday in any date in any year provided if and only if the weekday of the January 1st of that year is known. Hope you understood everything until this point.

 I simplified the big table to these two tables after thorough observation of the order in which the weekdays get repeated.

 If the weekday of the january 1st of the year is known then...................

Things to do in Table 2

The weekdays in red color in table 2 are the weekdays of the January 1^st s of the year. According to the year whether leap or non-leap select the column and see its coincidence with the row of the weekday of the January 1^st of the year. You will get a number.

Things to do in Table 3

See the coincidence of the row of that number with the date. You will get a weekday. That’s the weekday of your day.

When I made these two tables I thought of giving codes to the months and then find out the weekday of any date using the codes. I arbitrarily chose the code for Sunday to be 0(zero) and then for the successive weekdays the codes are 1,2,3,4,5,6. Then I thought about the month codes. For the coincidence of January and Sunday in table -2 the number is one and then the coincidence of 1 with the date 1 is a Sunday, therefore I decided that the code for January is 6 for which if the date 1 is added and the sum is divided by 7 the remainder is 0 which represents a Sunday. The codes for other months are found using the month code of January i.e. February's code is 2, etc.

In my next step I was thinking about how to find the weekday of January 1^st of any year easily. In that process I made the table shown above. : -

When I made a table for the years 1900 – 2000 I found that there was exactly a difference of one weekday between the January 1^st of 1900 and that of 2000

I found that the January 1^st of 1900 was Sunday and that of 2000 was a Saturday. I could find out the weekdays of January 1^st s of these years by applying Rule 1 in the reverse way. I considered that all years, which are divisible by 4, are leap years {that’s the mistake I did! Actually century years that are not divisible by 400 are not leap years}. As there was a one-day difference between the January 1^st s of two consecutive century years I could make the table very conveniently because the same weekday repeats after every 700 years. 

It was also equally important to replace the table in the former part of the page by some codes so that it looks simpler. In that course I made tables assigning values to weekdays as 0 – Sunday, 1 – Monday, etc and found the corresponding codes for months and thought that I could add 1 if the year is leap and the month is after February making Table -2 and Table -3. Then I merged everything.

Then it was published in Eenadu and in Indian Magazine of Human Experience. as in the tables given below. You can refer to these articles for reference and to know how to calculate from it.

At this point of time.. it was also checked for correctness by Osmania University Professor, Mr. Satyanarayana, where he stated this method to be unique and that it was different from the previous algorithms..

But later after several months I found that the century years which are not divisible by 400 are not leap years. So I modified Table 1 to this form: 

This is a table which replaces the table -1 of my calendar published in Eenadu so that it becomes an infinite year calendar.

Rules:-

1)The zero that you see in the last row (red) of the years corresponds to the 0 for the years 2000,2400,2800,etc. and is not meant to be used with the years1900,1800,2100,etc which are not divisible by 400.

2) You need to see the coincidence of the last two digits of the year with the remainder obtained when the first two digits of the year are divided by 4.

3)Add to it, the month code from table-2 and the date.

4)When the resulting sum is divided with 7, the remainder obtained gives the weekday from table-3.

With this I stopped making calendars containing tables in them and thought about the further simplification of the procedure so that it would be much more easier and simpler to use.