## How Many Days are there in a Leap Year?

Leap Year=366 Days

According to the Gregorian calendar, one year is 365 days. (How many days are in a year) However, one year is 365.242 days as counted astronomically. Well, what about this extra period? In case we do not include the extra period into the calendar, there will be a 25 day shift every 100 years and there will be a 6 months shift at the end of 720 years. There would be snow in the summer season with this shift. In order to get rid of this excessive 6 hours in every year, it was decided to include it into February every 4 years. In this way, we get rid of the seasonal shifts by including the excessive hours into February once in every 4 years.

Now let’s calculate:

1. 1st year, 6 extra hours
2. 2nd year, 6 extra hours
3. 3rd year, 6 extra hours
4. 4th year, 6 extra hours

There are 24 extra hours in every 4 years in TOTAL.

24 hours = 1 day.
The extra one day in every 4 years is included into February in order to prevent any possible shift in the calendar.

### How to Calculate in Which Years February Lasts 29 Days?

The accepted formula is determined as the years which are the multiply of the four. For instance, the years of 88, 1612, 1992, 1996, and 2004 are subjected to this rule, however, there are 2 exceptions:
Only the years which can be divided by 400 are the leap year in the years which are the multiplier of  100:
For instance, 1200, 1600, and 2000 are leap years, however, 1700, 1800 and 1900 are not leap years.
In addition to these, although some years can be divided by 400 but also divided by 4000 are not considered as a leap year:
For instance, 4000, 8000, 12000, 16000, 24000, 32000 and 48000 years will not be considered as a leap year although they can be divided by 400.

We have answered the question of how many days are in a leap year.  You can see the remaining time concerning our How many days until leap year subject.