The only real difference between the two terms is this: Leap years are years with one extra day, and leap days are that day. It's as simple as that!

A leap year is a year with an extra day, February 29th. It occurs every four years. The next leap year is 2020.

The purpose of a leap year is to keep the calendar year synchronized with the astronomical or seasonal year.

There are three different ways to calculate a leap year:

- The first way is to divide the year in two. If the first half is a leap year, then the second half is a leap year. This calculation works for any year except for the years 1600, 2000, and 2400.
- The second way is to take the last two digits of the year and divide them by four. If the result is zero, then the year is a leap year. This calculation works for any year except for the years 1600, 2000, and 2400.
- The third way is to take the last two digits of the year and divide them by four. If the result is zero, then the year is a leap year. This calculation works for any year except for the years 1600, 2000, and 2400.

There are two types of leap years: common years and leap years.

A common year has 365 days and a leap year has 366 days. The extra day in a leap year is February 29th.

In the Gregorian calendar, the days of the year are divided into weeks. There are 52 weeks in a year, plus one day (February 29th). This day is called a leap day.

A leap year has 366 days, divided into 52 weeks and 2 days. The 2 days are February 29th and February 28th.

In a leap year, February has 29 days. This is because there are an extra 24 hours in February, so one day is added to the month.