Calendar
This trick must be used when we need to calculate previous date from the given date.
Q1.) What was the day of the week on 17 January 1883?
STEP 1 :
First of all substract 1 with the year
1883 - 1 = 1882
STEP 2 :
Divide the year with 400 to check the number of leap year
1882 / 400 = 282
STEP 3:
100 years = 5 odd days so
282 year & 1 Jan to 17 January 1883
2 * 100 = 2 * 5 = 10 odd day
STEP 4:
Now again check leap year
82 year = 82 / 4 = 20 leap year
and subtract the leap year with 82 to calculate ordinary year
82 year = 20 leap year + 62 odinary year
STEP 5:
As we know
1 leap year = 2 odd day
1 ordinary year = 1 odd day
20 * 2 + 62 * 1 = 102
Now divide the total days with 7 and reminder will be odd days
102 / 7 = 4 odd days
STEP 6:
1 Jan to 17 January 1883
Number of Days in 1883 | ||
Jan | 16 | |
---|---|---|
Total No. of Days | 16 |