New Year. It’s all a Matter of Time, really.

The introduction of “Timekeeping” is a great opportunity to talk about different disciplines associated with it.  Whether at school or at home, choose ONE story at a time, and you will have a fiesta in the making about Weather, Astronomy, Astrology, Math, Mythology, and much more.

Night and Day, are at the heart of man’s questions and answers about timekeeping. During the day, the sun is constant, but at night, the moon changes, so it is no surprise that the first “Calendars” were Lunar Calendars.

 In Mesopotamia, Babylonians were the leading astronomers; they had a lunar calendar similar to the first Egyptian calendar which is still in use today for Jewish and Muslim Holidays.

The major disadvantage of a Lunar Calendar. The lunar month is 29.5 days long. Twelve lunar months are 354 days, approximately 11 days short of a solar year. Most Lunar calendars tried to correct this disparity by adding an extra month from time to time.

Julius Caesar followed the advice of Sosigenes, a learned Greek astronomer from Ptolemaic Egypt in Alexandria, added ninety days to the year 46 BC and introduced the “Julian Calendar” in 46 BC with 365 days + six hours. Adding one day to February every fourth years [leap year].

In the 1500s, due to minor discrepancy, the equinox happened ten days earlier than it should on March 21 and September 23. So, Pope Gregory XIII had a German Jesuit astronomer Christopher Clavius to solve the problem:

Every century year (or those ending in ’00’) should only be leap years if divisible by 400. This eliminates three leap years in every four centuries and neatly solves the problem. The result, in the centuries since the reform, is that 1600 and 2000 are normal leap years, but the intervening 1700, 1800 and 1900 do not include February 29, making it accurate to within one day in 20,000 years.

In 50 BC The Maya and Aztec calendars consisted of a year of 365 days, divided by 18 months of 20 days and the last month only had 5 days.

The Chinese Calendar [2070-1600 BC] It’s a lunisolar calendar that measures the phases of the moon, and also the position of the sun in the sky. the Chinese lunar calendar introduces a leap month every three years instead.