Name of the day Calculation

Without see the calendar you can’t say what the day of 30^th September 1982 was. It is boring to store old calendar. If you learn a rule you can easily say any day of any year.

Month	M
March	1
April	2
May	3
June	4
July	5
August	6
September	7
October	8
November	9
December	10
January	11
February	12

Day	D
Sunday	0
Monday	1
Tuesday	2
Wednesday	3
Thursday	4
Friday	5
Saturday	6

A= (2.6*M-0.2) +D+Y+(Y/4) +(C/4)-2*C

Hare, M= Month.
D= Day.
Y= Year.
C= First two Numbers of the year

Example0: 30/09/1982

A = (2.6*M-0.2) +D+Y+(Y/4) +(C/4)-2*C
= (2.6*7-0.2) +30+82+ (82/4) + (19/4)-2*19
= 18+30+82+20+4-38
= 116

Now: 116/7= mod 4

So the day was Thursday.

Example1: 18/10/2007

A = (2.6*M-0.2) +D+Y+(Y/4) +(C/4)-2*C
= (2.6*8-0.2) +18+07+ (07/4) + (20/4)-2*20
= 20+18+07+1+5-40
= 11

Now: 11/7=mod 4

So the day was Thursday