How many days are in a leap year?

A leap year consists of 366 days, which includes an extra day added to the month of February, making it 29 days instead of the usual 28. Leap years occur every four years as a way to keep our calendar synchronized with the Earth's revolutions around the Sun. The adjustment is necessary because a year, based on Earth's orbit, is approximately 365.25 days long. By adding an extra day every four years, calendars stay accurate over time. Therefore, in terms of total days, a leap year unmistakably contains 366 days.