Ancient Egyptian Calendar (Civic)

by Erin Potter

khafre at sunsetThe ancient Egyptian calendar was invented over 5000 years ago. It was originally based on the lunar cycle of 12 months, which the Egyptians grouped into three seasons of four months each to coincide with the rise and fall of the waters of the Nile. However, although the flooding of the Nile began each year around the end of June, the floods occurred within a range of 80 days and were not accurate enough to base a calendar on. So the ancient Egyptians, having noticed that the Nile’s rising coincided with the heliacal rising of the star Sirius, the brightest star in the sky, based the year on the cycle of its reappearance.

The beginning of the year, also called "the opening of the year", was determined by the appearance of the star Sirius, in the constellation of Canis Major, which occurred around June 21st. However, because the rising of Sirius is a stellar event, which means it occurs every 365 ¼ days, the rising of the star did not precisely match the calendar, which was based on the lunar cycle and so had an average of 354 days--11 days less than a solar year. This meant that the rising of the star would very quickly be out of sync with the calendar. To correct this, the Egyptians introduced an extra month to create a “Great Year” of 384 days every 2 or 3 years.

However, because this calendar was either not accurate enough, too complicated, or unsuitable for economic and administrative purposes, a standard calendar was introduced in the Old Kingdom to run along side the lunar calendar. This calendar, which probably resulted from counting the number of days between successive risings of Sirius.

The new “Civic” calendar year was divided into 3 seasons, each with four months. Each of the 12 months had 30 days divided into 3 decades (weeks) of 10 days each for a total of 360 days. The seasons of the Egyptian calendar were believed to have been chosen to correspond to the cycles of the Nile which was central to the life of the Egyptians. Because they lived an agrarian lifestyle the seasons were named after the significant events for farming. Translated to our Gregorian calendar, the dates of these seasons seem to vary considerably as do the names of both the seasons and the months. For example, the season of Akhet, is considered by one reference to occur between August 29th and December 26th, whereas another references place it between June 21st and October 21st .

AkhetAkhet was the time of the year that the Nile flooded. The name 'Akhet' literally means inundation. This occurred normally between July and December. During this time irrigation canals redirected water from the Nile to the more arrid areas.


ProyetProyet was the time of the year when the Nile receded. Because the temperatures were much cooler than other times of the year this was the perfect time for the farmers to sow their crops. Proyet occurred normally from December to March.


ShomuShumo was summertime for the Egyptians. Lasting from March to July it was a dry time when the crops were harvested and was often one of the busiest times of the year. Because the crops were now in it was also the time when the tax collectors showed up for the Pharoah's share.


Mastaba

Season

Month


Akhet
"inundation"

Tekh

Menhet

Hwt-Hrw

Ka-Hr-Ka


Proyet
"emergence"

Sf-Bdt

Rekh Wer

Rekh Neds

Renwet


Shomu
"low water"

Hnsw

Hnt-Htj

Ipt-Hmt

Wep-Renpet

Because this public calendar with 360 days was too short to coordinate with the agricultural and lunar calendar, a five day month (Epagomenal), was added at the end of the year with religious festivities to celebrate the birthdays of the gods. With the addition of these 5 intercalary days or “the days upon the year,” the total number of days was brought up to 365 days.

Although the ancient Egyptians were off in their estimation of the actual length of the solar year by only ¼ day, in time this discrepancy added up. The civic calendar was slipping at a rate of a quarter of a day per year. Although they could have corrected it be having 6 intercalary days in the last month instead of 5, once every 4 years, the ancient Egyptians instead added a third year, a civil lunar year which was not tied to the rising of Siruis.

In the original lunar calendar the months were simply numbered according to where they fell in the season rather than named; however From the New Kingdom on, the months are often named.

Civil dates (for the common person) were usually written as the number of the month in the season, followed by the season’s name and then by the number of the day in the month and finally the year and ruler. When each ruler ascended to power the year count would restart. Sometimes the count would restart beginning with the first full year of the ruler and the time before that would be listed also as the first year, but with references to allow someone to understand the difference between the two (even if they were very subtle). For example: Second Month of Akhet, the13th day in the fourth year of the rule of Tutmosis III.

In 238 BCE, Ptolomy III replaced the civil lunar year with a system where every four years there was 6, rather than 5 epagomenal or intercalary days, in other words, a leap year. However, the Egyptians were very resistant to this change. It wasn’t until the Roman Emperor Augustus introduced it (25 BCE) that it was effectively implemented.

The Egyptian calendar had an importance well beyond the Egyptians’ use of it. Astronomers throughout the ancient times and the Middle Ages used the old Egyptian calendar instead of the Alexandrian calendar because its regularity in both the number of day in the months and the year made their calculations much easier. Such regularity was highly desirable because the ancient peoples did not have Arabic numerals nor the concept of zero to make complex mathematics manageable.

Click here to see the Civic Calendar for this year.

Egyptian Dates

Civil dates (for the common person) were usually written as the number of the month in the season, followed by the seasonís name and then by the number of the day in the month and finally the year and ruler. When each ruler ascended to power the year count would restart. Sometimes the count would restart beginning with the first full year of the ruler and the time before that would be listed also as the first year, but with references to allow someone to understand the difference between the two (even if they were very subtle). For example: Second Month of Akhet, the13th day in the fourth year of the rule of Tutmosis III.

Hours and Telling Time

Unlike most of the ancient peoples, who started the next day at sunset the Ancient Egyptians started their new day at sunrise. Their day was divided into twelve hours, numbered one to twelve, and the night into another twelve, numbered thirteen to twenty four. However, the hours were not all the same length. In the summer the hours of the day were longer than the hours of the night. In the winter it was the other way around.

During the day, because the skies were usually clear, they measured the passing of the hours using a sundial. At night the passing of the hours was determined by the rise and fall of the stars. Because different stars rise at different times, depending on the seasons, the darkness hours could be determined by the rising of certain special stars, which were called decans. Stars were often painted on the ceilings of the pyramids so that the dead individual.

Later the Egyptians used water clocks ( clepsydra) to tell the time more accurately than they could with a sundial or the stars.

Learn to Read Hieroglyphs

  1. References and Links
  2. Grade 6 Egypt Project