10 Interesting Facts About The Calendar

Mayan Calendar

1: Ancients Used Phases of Moon to Measure Time

Ancient people used to measure time by charting the phases of the moon from new to full, which is the likely origin of the word month, and occurs approx. once every 29 and a half days. Some of the Oldest Lunar Calendars marking the month and days have even been found by archaeologists inscribed into sticks and animal bones, or discovered in beautiful cave art found in France and Germany.

2: Egyptian Year Began When Sirius Rose With The Sun

The ancient Egyptian calendar dates back to 4236 BCE, and divided the year into 12 months, with the first day of their year beginning when the sky’s brightest star Sirius, which they identified with the goddess Isis, rose with the sun. Interestingly, the length of time it takes for this heliacal rising of Sirius to occur is exactly the same as our solar year (365.242199 days), and so the Egyptian year was calculated to be 365 days long, with each month allotted 30 days, and an extra 5 festival days added to make up the difference.

3: Mayan Calendar More Accurate Than Our Gregorian System

The Mayan calendar dates back to at least the 5th century BCE, and by 900 AD had been refined into a complex, but highly accurate calendar, even more precisee than the modern Gregorian calendar we use today. While the Gregorian calendar gains three days in every 10,000 years, for example, the Mayan calendar loses just two days over the same period.

Amongst the three calendars used by the Mayans, one used a 260 day cycle based upon the movements of the planet Venus, which was then combined with a solar year period of 365 days to generate a recurring 52 year period called a ‘Calendar Round’, similar to our concept of a “century.”

4: Julian Calendar Out By 11½ minutes A Year

Originally, the Roman calendar consisted of 10 months spread across 304 days, starting with March and ending in December, but in 700 BCE the months of January and February were then added, increasing the year’s length to 355 days. In 45 BCE, Julius Caesar made further reforms by adding another ten days, and a leap day to February every four years, and subsequently changed  the Roman year to his Julian calendar.

Although significantly more accurate than its predecessors, an average Julian year lasted 365.25 days, instead of the actual solar day length of 365.2422, thus resulting in an error of 11½ minutes a year, or one day every 130 years.

5: Gregorian Calendar Accurate To 26 Seconds A Year

10 Interesting Facts About The CalendarThe Gregorian calendar was introduced on 24th February 1582 by Pope Gregory XIII, to correct the 11½ minutes lost a year by the Julian calendar, and so bring back alignment with the Earth’s revolutions around the sun. A more precise method of calculating Leap Years was then devised basically requiring it to be divisible by 4 to count, unless it is also divisible by 100 in which case it is NOT a leap year.

Differences between Catholic and Protestant countries in Europe, however, meant that the papal move was viewed with suspicion and Germany didn’t switch over until 1700 and England and the Eastern USA held out until 1752.

While somewhat more accurate than its predecessor, the Gregorian calendar we use today still differs from the solar year by 26 seconds each year or one day every 3,323 years.

6: BC/AD System Introduced in 525 AD

The BC/AD system was devised by a monk called Dionysius Exiguus in 525 AD, but he incorrectly placed Jesus‘ birth as 1 BC because of an old text which related that Jesus was born in the 28th year of the reign of Augustus Caesar. However, Augustus was accepted as Emperor four years before the official ceremony, and so Jesus was probably born around 5 or 6 BC. The  historical and biblical wisdom states that Christ was born in the reign of Herod the Great, a king who was known to have died in 4 BC.

Jesus Christ’s first year of life was officially named by Pope John as 1 AD. The year in which this happened was AD 532. It was also 754 A.U.C (denotes the founding of Rome by Romulus and Remus).

7: Chinese Calendar Years Named After Zodiac Animals

The Chinese Calendar is believed to date back to 2637 BCE, and while today the Gregorian calendar is used for administrative and commercial purposes, in China its traditional 12 month lunisolar calendar is still used for religious purposes. One of its quirks is that it includes leap years containing 13 months, and another is that its years are named and counted according to the 12 Chinese zodiac animals which are repeated in sequence 5 times every 60 year cycle. These zodiac animals are the rat, ox, tiger, hare or rabbit, dragon, snake, horse, sheep, monkey, rooster, dog, and pig.

Finally, the Chinese New Year is the longest holiday in the Chinese calendar, and according to legend a beast called a Nian would emerge from its hiding place once a year to attack humans. Fortunately, these mythological creatures are sensitive to explosions, fire and the colour red and so the traditional New Year celebrations are marked by fireworks, loud banging, and lots of red costumes.

8: Why Seven Days in A Week?

The earliest record of a seven-day week dates back to 600 BCE ancient Babylon, where a holy day was celebrated every seven days starting with a new moon. This period of days corresponds to the main phases of the moon with each quarter falling roughly seven days apart, or evey 7.3825 days.

9: Origin Of Names Of The Days

The Greeks named the days of the week after the sun, the moon and the five known planets at that time which corresponded to the gods  Ares, Hermes, Zeus, Aphrodite, and Cronus. The Romans later substituted their equivalent gods so that for them the days of the week became Dies Solis, Dies Lunae, Mars, Mercury, Jupiter, Venus, and Saturn. The first Christian Roman Emperor Constantine then made the seven day week official in 321AD.

These days, it is mostly the Germanic and Norse gods that live on in the names of the days of the week, including Tuesday (Tiw), Wednesday (Woden), Thursday (Thor), and Friday (Freia).

10: Origin Of Names Of The Months

(A more detailed description can be found here)

January: named after Janus
February: in honour of Februus
March: named after Mars
April named after Aphrodite
May named after Maia
June: named after Juno
July: named after Julius Caesar
August: named after Augustus Caesar
September: from the Latin for seven
October: from the Latin for eight
November: from the Latin for nine
December: from the Latin for ten