Egyptian calendar

From Wikipedia, the free encyclopedia

The ancient civil Egyptian Calendar, known as the Annus Vagus or "Wandering Year", had a year that was 365 days long, consisting of 12 months of 30 days each, plus 5 extra days at the end of the year. The months were divided into 3 "weeks" of ten days each.

This calendar was in use by 2400 BCE, and possibly before that. It was used throughout antiquity. It was used by astronomers in the Middle Ages because of its mathematical regularity.

The Egyptian calendar was simple, but it is neither a lunar nor a solar calendar. Months do not correspond to lunar months, and years do not correspond to solar years. The Egyptians were aware of this, and calculated their seasonal year by the stars, to be the time between successive heliacal risings of the star Sirius (which the Egyptians called Sothis). The heliacal rising of Sothis returned to the same point in the calendar every 1460 years (a period called the Sothic cycle). The difference between a seasonal year and a civil year was therefore 365 days in 1460 years, or 1 day in 4 years. Similarly, the Egyptians were aware that 309 lunations nearly equalled 9125 days, or 25 Egyptian years, which was likely used in the construction of a secondary lunar calendar.

According to the Roman writer Censorinus, the Egyptian New Year's Day fell on July 20 on the Julian Calendar in 139 CE, which was a heliacal rising of Sirius in Egypt. From this it is possible to calculate that the previous occasion on which this occurred was 1322 BCE, and the one before that was 2782 BCE. This latter date has been postulated as the time when the calendar was invented, though earlier historians tended to push it back another whole cycle, to 4242 BCE.

In 238 BCE, the Ptolemaic rulers decreed that every 4th year should be 366 days long rather than 365. That practice was not followed, however, until the introduction of the "Alexandrian Calendar" in 22 BCE by Augustus. Calendars in use today (the Coptic Calendar and the Ethiopian calendar) are similar, as was the French Revolutionary calendar.

British orrery maker John Gleave represented the Egyptian calendar in a reconstruction of the Antikythera mechanism.

For most of Egyptian history, the months were not given individual names but rather were numbered within the three seasons of Akhet (Inundation), Proyet (Emergence), and Shomu (Harvest). During the New Kingdom, however, each month was given its own name. These eventually evolved into the Hellenistic names that were used among others for chronology by Ptolemy in his Almagest, and are still used today by the Coptic Church. The convention amongst modern Egyptologists is to number the months consecutively using Roman numerals.

The Egyptian calendar is still observed in Egypt today, especially by the fellahin who rely on it to calculate the agricultural seasons. It is also associated with many local festivals throughout the country.

No.	Seasonal Names	Individual Names	Coptic Names	Greek Names	Modern names
I	First of Akhet	Tekh	Thout	Thoth	Tout
II	Second of Akhet	Menhet	Paopi	Phaophi	Baba
III	Third of Akhet	Hwt-Hwr	Hathor	Athyr	Hatour
IV	Fourth of Akhet	Ka-Hr-Ka	Koiak	Choiak	Kiahk
V	First of Proyet	Sf-Bdt	Tobi	Tybi	Touba
VI	Second of Proyet	Rekh Wer	Meshir	Mechir	Amshir
VII	Third of Proyet	Rekh Neds	Paremhat	Phamenoth	Baremhat
VIII	Fourth of Proyet	Renwet	Paremoude	Pharmouthi	Baramouda
IX	First of Shomu	Hnsw	Pashons	Pachon	Bashans
X	Second of Shomu	Hnt-Htj	Paoni	Payni	Ba'ouna
XI	Third of Shomu	Ipt-Hmt	Epip	Epiphi	Abib
XII	Fourth of Shomu	Wep-Renpet	Mesori	Mesore	Mesra

[edit] External links

• Date Converter for Ancient Egypt
• Calendrica Includes the Egyptian civil calendar with years in Ptolemy's Nabonassar Era (year 1 = 747 BC).
• CIVIL4.0 On this page CIVIL4.0 may be found, a tiny DOS program (Zipped, 25kB) to convert Egyptian Civil dates into Julian and Gregorian dates, B.C. and A.D.
• Detailed information about the Egyptian calendars, including lunar cycles