How many weeks are in 15 years?

Answer 1

1 year = 365 days = 52 weeks 1 day.

(1) If year 1 or year 2 of the 15 year period was a leap year then there would be 4 leap years in the period.

(2) If year 3 or year 4 was a leap year then there would be only 3 leap years in the period.

Each leap year gives 1 extra day.

Condition (1) 15 years = 15 x 52 weeks + 15 days + 4 days = 782 weeks + 5 days.

Condition (2) 15 years = 782 weeks + 4 days.

NOTE : Deduct 1 further day if the 15 year period spans a year number not divisible by 400 (for example 1900)