Finding the DAY for any given DATE
1) Let the given date is 14-7-2021.
2) The formula is [ K + { (M-2) x 2.6 – 0.2 } + C/4 + D/4 +D-2C] divided by 7
3) Where K is the date M is the month C is the century D is the last two digit of the year
4) [ 14 + { (7-2) x 2.6 – 0.2} + 20/4 + 21/4 + 21 – 40 }] divided by 7
if M – 2 is zero or -1 ( Feb or Jan) , less one from the year ( D ) and add 12 months to month M.
Drop all the residuals/fractions in all cases and take the whole number only
5) [ 14 + 12.8 + 5 + 5 + 21 – 40] divided by 7
6) {14 + 12 + 5 + 5 + 21 – 40) divided by 7
7) 17 / 7 = 2 and 3/7
If the reminder comes ZERO, it is SUNDAY. 1/7 means MONDAY, 2/7 means Tuesday, 3/7 means WEDNESDAY, 4/7 means THURSDAY, 5/7 means FRIDAY AND 6/7 means SATURDAY.
Hence 14-7-2021 is Wednesday .
9) Try for other dates also.
By T.R.Jothilingam,Retd.Railway Station Supt., Madurai
9442810486