Sothic cycle
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The Sothic cycle is a period of about 1,460 ancient Egyptian civil years associated with the heliacal rising of Sirius, known to the Egyptians as Sothis. It results from the difference between the 365-day civil calendar and the tropical year.
Because the Egyptian civil calendar had no leap day, its dates shifted by roughly one day every four years relative to the seasons and the annual appearance of Sirius before sunrise.
After approximately 1,460 civil years, the calendar date and the heliacal rising of Sirius returned to nearly the same relationship. The cycle has been used in attempts to date events in ancient Egyptian chronology.
Interpretation is complicated by observational location, atmospheric conditions, calendar reforms, uncertain historical records, and the exact length assigned to the year. The Sothic cycle remains important in studies of ancient astronomy and chronology.
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- Source / publisher: Wikipedia
- URL type: WWW
- Credits: Wikipedia
- URL: https://en.wikipedia.org/wiki/Sothic_cycle