How many days are there in a leap year?

In a leap year, there are 366 days rather than the typical 365 days found in a common year. This additional day is added to the month of February, which has 29 days in a leap year instead of its usual 28 days. Leap years occur every four years to help synchronize the calendar year with the astronomical year, as the Earth takes approximately 365.25 days to complete one orbit around the Sun. The extra day compensates for this fractional day and keeps our calendar aligned with the seasons.