Just the facts: Leap year info and history

Our now current year 2020 is a Leap Year. The Gregorian calendar is the standard calendar used in the United States and in most countries of the world.

Using this calendar, most years that are multiples of 4 are known as Leap Years. In each Leap Year, the month of February has 29 days instead of the standard 28 days. Adding this one extra day to the calendar every four years compensates for the fact that a period of 365 days is slightly shorter than a tropical year.

The actual duration of the standard tropical year is 365.25 days, and by adding one day to our calendar every four years, the total number of days over four years are now made equal.

Following is the astronomical reason for us to have a leap year. Every four years, we add this extra day to the calendar on February 29, and this is also known as Leap Day. Put simply, these additional 24 hours are built into the calendar to ensure that it stays in line with the earth’s movement around the sun. While the modern calendar contains 365 days, the actual time it takes for Earth to orbit its star is slightly longer, and is actually 365.25 days.

This slight difference might seem negligible, but over decades and centuries that missing quarter of a day per year can add up. To ensure consistency with the true astronomical year, it is necessary to add in an extra 24 hour day every 4 years. This makes up for the 6 hours of time that needs to be added for each year to keep the calendar in synch with the seasons.

The Roman dictator Julius Caesar is considered to be the creator of leap year. The ancient Roman calendar system was previously based on a total of 355 days in one year, and this was a full 10.25 days shorter than a solar year, which is the length of time it takes the Earth to make one complete orbit around the sun.

The Roman officials then determined they had to adjust their calendar to keep their calendar system in line with the seasons. Caesar then consulted with top Roman astronomers and the decision was made in 46 B.C. to add one day every four years to make up the discrepancy between the lunar and solar calendars.

Of interest, by having the extra day in our 2020 Leap Year, many of our favorite 2020 holidays will be falling on Fridays and Saturdays. If we complained about holidays falling on mid-week days in the past, we won’t have a lot to complain about in 2020.

Check out the following 2020 holiday dates. Valentine’s Day, 2020, is on a Friday, July 4, 2020, is on a Saturday, Halloween, 2020, is on a Saturday, Christmas, 2020, is on a Friday and our 2021 New Year will start with a three-day weekend, since Jan. 1, 2021, falls on a Friday.

Happy 2020 New Year and Happy Leap Year.

EDITOR’S NOTE: Dr. Jim Surrell is the author of “The ABC’s For Success In All We Do” and the “SOS (Stop Only Sugar) Diet” books. Requests for health topics for this column are encouraged. Contact Dr. Surrell by email at sosdietdoc@gmail.com.