We know that leap year occurs after every four years. Earth revolves around the sun in 365 days, five hours, 48 minutes and 46 seconds but we take one year of 365 days. There is still five hours left for the earth to complete its revolution around earth which is approximately Ã‚Â¼ of a day. So to compensate with this difference experts had added a day in the month of February after every four years. If this would not be done then seasons will not match with the months and after 700 years winter will be in July and summer in January. To avoid all this we add an extra day in February. So leap year has 366 days.
Ancient civilizations had a variety of ways to accommodate for this â€â€ after all, harvests, rituals, and celebrations all were pegged to specific days on a calendar. Many of the accommodations involved complicated maneuvers that often made things even worse, like adding a month to certain years.
The idea of a leap day was introduced in the first century BC by Roman leader Julius Caesar, who decided that every fourth year would have an extra day added to offset the shift. While this was a good plan, it wasn’t perfect. Given that each year had only an extra .242 of a day, over time, the extra day added every four years also threw the calendar off â€â€ by one day every 128 years.
In 1582, the Gregorian calendar introduced by Pope Gregory XIII remedied this problem by adopting new rules for calculating leap years, which we use to this day:
Â· To be a leap year, the year must be evenly divisible by four. Â· Any year that is evenly divisible by 100 is not a leap year â€â€ unless it is also evenly divisible by 400.