I am going to tell you one of the fastest method to find to day of any date from the year \(1900 to 1999\) just by giving out 4 inputs. For this method you must know the code of the day and months.
These are the codes for the month:-
These are the codes for the days:-
Let's take an example:-
Find which day was \(19 July 1967\)
Let's start solving by giving the four inputs:-
--> Date = \(19\)
--> Last 2 digits of the year = \(67\)
--> Number of leap years occurred in that century = 67/4 = \(16\)
Note that for this input JUST TAKE THE QUOTIENT NOT THE REMAINDER.
--> Code of the month = \(0\)
By adding all the inputs we get the answer \(102\)
Now, divide the result by 7 and ONLY TAKE THE REMAINDER.
= \(102 / 7 \) = 14 and the remainder is 4.
And 4 is the code which day you have to find.
And 4 is the code of \(Wednesday\)
So, the answer is \( 19 July 1967 was Wednesday.\)