<P> Current knowledge of the earliest development of the Egyptian calendar remains speculative . A tablet from the reign of the First - Dynasty pharaoh Djer (c. 3000 BC) was once thought to indicate that the Egyptians had already established a link between the heliacal rising of Sirius (Ancient Egyptian: Spdt or Sopdet, "Triangle"; Greek: Σῶθις, Sō̂this) and the beginning of their year, but more recent analysis has questioned whether the tablet's picture refers to Sirius at all . Similarly, based on the Palermo Stone, Scharff proposed that the Old Kingdom observed a 320 - day year but his theory has not become widely accepted . Some evidence suggests the early civil calendar had 360 days, although it might merely reflect the unusual status of the five epagomenal days as days "added on" to the proper year . </P> <P> With its interior effectively rainless for thousands of years, ancient Egypt was "a gift of the river" Nile, whose annual flooding organized the year into three broad seasons known to the Egyptians as: </P> <Ul> <Li> Flood (Ancient Egyptian: Ꜣḫt, sometimes anglicized as Akhet), </Li> <Li> Emergence (Prt, sometimes anglicized as Peret), and </Li> <Li> Low Water or Harvest (Šmw, sometimes anglicized as Shemu). </Li> </Ul> <Li> Flood (Ancient Egyptian: Ꜣḫt, sometimes anglicized as Akhet), </Li>

What are the three seasons of the egyptian calendar