1. Calendar Important Formula's1 ordinary year = 365 days = (52 weeks + 1 day.) 1 ordinary year has 1 odd day. 1 leap year has 2 odd days. = (76 x 1 + 24 x 2) odd days = 124 odd days.
2.
We know that in the calendar we have,
- 1 week = 7 days – Mon Tue Wed Thu Fri Sat Sun.
- 1 year = 52 weeks + 1 odd day (extra day).
- Leap year = 52 weeks + 2 odd days.
- Ordinary year = 28th Feb.
- Leap Year = 29th Feb.
3. Odd days in ordinary year = (52 weeks + 1) days. Odd days in a leap year = (52 weeks +2) days. So odd days in 100 years will be (76 x 1 + 24 x 2) which is 124 odd days. This can also be written as 17 weeks + 5 days.