News

Leap year just a leap away

By Scott Wagar

02/21/2012

February is a unique month this year as February has 29 days instead of 28 days, which is referred to as leap year and grants an additional day in 2012. Leap year is important because it keeps the seasonal year (or solar year) corresponding with the standard calendar year.

When one looks at Leap Year mathematically, the calendar year is organized to fall perfectly into 365 days. However, solar seasons do not fall perfectly in 365 days each year, because one astronomical year equals 365.2422 days, which means that the solar year is an additional six hours longer than the calendar year.

To correct this on the calendar, every four years in February an additional day is added onto this month to equal the 24 hours, or one day, that has been lost in the past four years, corresponding with the solar and calendar years.

Historically, Leap Year dates back to 46 B.C. during the reign of the Roman Emperor Julius Caesar. At that time, Caesar requested an astronomer by the name of Sosigenes to fix the calendar year to equal 365 days, or 52 weeks in a 12 month year.

For Caesar, it was important to have a more configured calendar because at this time in the Roman Empire, citizens followed a Greek Lunar calendar, which had 354 days. With this method, the Empire had to add an additional month every few years to make the correction with solar and calendar years.

Sosigenes fixed the Greek calendar by adding additional days to different months throughout the year to equal a 365-day year. However, the Julian calendar made one solar year equal 365.25 days; or, a solar year that was 11 minutes and 14 seconds longer than the Julian calendar, which after a 128 years, the calendar year would be one day shorter than the astronomical almanac. To correct this issue, Sosigenes added an extra day to February to every year that was evenly divisible by four.

In 1582, Pope Gregory XII made the decision to correct the Julian calendar to make the calendar and solar years even closer together because he wanted to make certain that the vernal equinox would stay close, or on, the date of March 21. This date was important to Gregory because Easter is based on the astronomical calendar, meaning that the Christian holiday falls on a Sunday fourteen days after the first full moon of March 21.  

With the Christian church concern about Easter and the vernal equinox, the problem was corrected when Pope Gregory’s mathematician devised that century years were not leap years unless they are divisible by 400.

An example of this is the year 1600 (1600/4 = 400) and 2000 (2000/4 = 500), which are leap years, but the year 1700 (1700/4 = 425) and 1900 (1900/4 = 475) were not. This formula made the length of the calendar year 365.244 days, which reduced the calendar error to only one day in 3322 years.

Today, we use the Gregorian calendar.

In the history of leap years, cultural traditions have been established, some by the astronomical calendar, while others through folklore.

In a non-leap year, or what is called a common year, there are 52 weeks in a year plus one day. So, if individuals are born on a Monday in a common year, their birthday the following common year will be on a Tuesday. However, during a leap year, which is made up of 52 weeks plus two-days, individuals born on a Monday will jump over a Tuesday and fall on a Wednesday, which established the term “leap year.”
Individuals born on February 29 (instead of February 28, the last day of February in a common year) are often called a “leaper” or “leapling,” and normally are considered only to be a quarter of their age next to those who have a birthday every year whether it is common or leap year. However, leap year birthday are traditionally celebrated on Feb. 28 or March 1. Most celebrate their birthdays on March 1 because it is the next day after Feb. 28.

In the United Kingdom, it is tradition that women can propose marriage during a leap year. One of the most traditional folklore stories on this issue is that Queen Margaret of Scotland, at the age of five and living in Norway, made a law that stated that if a man refused a marriage proposals during a leap year, the man would either have to pay the woman back with a kiss or one pound of silk to assist her in making a silk dress.

In Greece, marrying on a leap is considered bad luck.
When it comes to agriculture and livestock, at one time it was considered unlucky to plant beans and peas during leap years because people believed the vegetables didn’t grow in a proper manner.

When it came to sheep, Scottish producers believed a proverb that stated, “Leap year was never a good sheep year.”

Some countries and religions believe in a lunisolar calendar, which means that they leap a month instead of day. In the Hebrew calendar, a 13th month is added seven times every 19 years to its 12 months common year to keep its calendar and seasons in place.

Next week as we celebrate the leap year with the 29th day in February, granting us 366 days this year instead of 365, the leaping of the day into a evenly devised seasons with the calendar year will keep some people younger; keep Easter on its chosen time of the season; agriculture on an even keel and folklore rich with exciting tales.