Gupta's Perpetual Calendar for Finding the Day of the Week

We take the following steps :-

1. Divide the year in question by 400.

2. (a) Find out the letter at the head of the column in which the remainder lies.

(b) If however the remainder be followed by a dot, and the month in question be not January or February, use the letter at the head of the column in which the dot lies.

3. Find this letter in the row of the month in question.

4. Look down the corresponding column and find the week day corresponding to the date in question.