Editing History of science (section)

====Calendar====
The ancient Egyptians even developed an official calendar that contained twelve months, thirty days each, and five days at the end of the year.<ref name= "lindberg2007a"/> Unlike the Babylonian calendar or the ones used in Greek city-states at the time, the official Egyptian calendar was much simpler as it was fixed and did not take [[Lunar phase|lunar]] and solar cycles into consideration.<ref name= "lindberg2007a"/>