February 29 has been a long time confusion as to whether it is an extra day that is occasionally added to the calendar after some certain years or it’s a real date in the calendar. Giving birth on February 29 has always been a mystery because the child will have to celebrate his birthdays every three years, if he’s a type that does. Now, the question is: “Is February 29 actually a real date in the calendar or a day added after some fixed years?”
A complete year is the time it takes the Earth to orbit the sun. we were made to believe that it takes 365 days for the earth to orbit the sun –in the real sense, that’s not strictly true. A true year – known as a tropical year, solar year, astronomical year or equinoctial year – is the time it takes the sun to pass from vernal (or spring) equinox to vernal equinox. That’s 365 days, 5 hours, 48 minutes, and 46 seconds, or 365.2422 days to be precise. So there’s roughly a six-hour margin of error in every “common year.” Leap years compensate for the extra 0.2422 of a day. Failing to compensate for these “extra” hours would send us out of sync with the seasons – by about 24 days after only 100 years.
The calculation is simple:
It takes 365 days, 5 hours, 48 minutes, and 46 seconds, or 365.2422 days for the earth to orbit the sun
When 5 hours, 48 minutes, and 46 seconds or 0.2422days accumulate to 24hours (a complete day), we would then add a day to our calendar to maintain sync with the earth’s orbit
A common year is 365 days, which is about a quarter of a day shorter than a tropical year. At 366 days, leap years are three-quarters of a day longer than a tropical year. Over time, the combination of common and leap years keeps us roughly in sync with the Earth’s orbit of the sun.