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Egyptian Calendars with an Astronomical Basis

Page history last edited by PBworks 13 years ago

 Egyptian Calendars

with an astronimical basis



For over 2,000 years, the Egyptians used three calenders concurrently. Each of the calenders had it's own use:



  • The civil calendar was likely first invented by them. It had 12 months, each had 30 days with 5 days extra.
  • The lunar calendar determined agricultural events such as when to plant and harvest.
  • The quasi-lunar calendar determined dates of festivals.




Lunar Calendar


The Egyptians one day noticed the bright star, Sirius, shined bright right before dawn days before the flood of the Nile began. This was important to mark because they depended on the river for their crops and source of food.  As they depended on the appearance of Sirius, they developed a calendar around it and so came the lunar calendar.  Like many other lunar calenders it followed by sidereal calendar.




Civil Calendar


After the lunar calendar was developed, there were certain problems and a new calender was invented. This calendar consisted 360 days with 5 days extra for feasting and celebration. It had three seasons, why were four months long with 30 days each.



Lunar vs. Civil


The two calendars had different systems and eventually did not correspond with one another. The lunar calendar followed the appearance of Sirius and its months would correspond with the seasons. On the other hand, the civil calendar moved through the seasons because it was one-fouth shorter than the solar year. Thus, every four years it was behind the solar year by a day.


A new calendar was then developed. It was based off the civil calendar and not on the sighting of Sirius. It was intended to gather dates of religious celebrations and duties. In order to keep it aligned with the civil calendar, they inserted a month every time the first day of the lunar year happened before the first day of the civil year. They did keep the older lunar calendar because it corresponded with the seasons and aided in agriculture.





>> http://www.lasalle.edu/~smithsc/Astronomy/calendars.html

>> http://www.webexhibits.org/calendars/calendar-ancient.html#egypt

>> http://www.mnsu.edu/emuseum/prehistory/egypt/dailylife/calendar.html


Comments (2)

Anonymous said

at 12:43 pm on Oct 14, 2008

It was good that you wrote about all three of the calendars that the egyptians used, however I think it would be even better if you put in some more info on the astronomy behind the calendars. The civil calendar lack detail.

Anonymous said

at 12:42 pm on Oct 14, 2008

The web page was well done and provided a lot of interesting information, but I think that you should have added some pictures so your presentation could have some sort of visual.

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