How to calculate the number of days between two given dates? (Leap year obstacle)

Question

• Any year evenly divisible by 400 is a leap year (e.g., 2000 was a leap year).
• Any other year evenly divisible by 100 is not a leap year (e.g., 1700, 1800 and

Answer 1

You don't need nested conditionals at all for this.

Hint: instead of trying to determine whether a given year is a leap year, try to determine the total number of leap days that came before it.