Number of days more than the complete weeks are called odd days in a given period.
A leap year has 366 days as the month of February, in the Leap year, has 29 days. Every year is divisible by 4 is a leap year, if it is not a century. Except for the 4th century, no other century is a leap year.
Examples :
Each of the years 1948, 2004, 1676 etc. is a leap year.
Each of the years 400, 800, 1200, 1600, 2000 etc. is a leap year.
None of the years 2001, 2002, 2003, 2005, 1800, 2100 is a leap year.
The year which is not a leap year is called an ordinary year. An ordinary year has 365 days.
1 ordinary year = 365 days = (52 weeks + 1 day)
1 ordinary year has 1 odd day
1 leap year = 366 days = (52 weeks + 2 days)
1 leap year has 2 odd days
100 years = 76 ordinary years + 24 leap years
= (76 * 1 + 24 * 2) odd days = 124 odd days
= (17 weeks + 5 days) 5 odd days
Day Codes :
0 = Sunday
1 = Monday
2 = Tuesday
3 = Wednesday
4 = Thursday
5 = Friday
6 = Saturday
1 year = 12 months
12 months = 52 weeks
1 week = 7 days
Ordinary year = 52 weeks + 1 odd day
Leap year = 52 weeks + 2 odd days
Odd days are the number of days more than a complete week or extra days in a year.
Number of odd days in 100 years = 5
Number of odd days in 200 years = (5 * 2) 3 odd days
Number of odd days in 300 years = (5 * 3) 1 odd day
Number of odd days in 400 years = (5 * 4 + 1) 0 odd day
Similarly, the 800th year, 1200th year, 1600th year, 2000th year etc have 0 odd days