Every ancient civilization had some system to track time. The ancient Egyptians, being an agricultural society, organized their calendar according to the cycles of the moon and the agricultural seasons. Most scholars agree that the Egyptian day began at dawn, rather than sunrise. 
The day was divided into 24 hours: 12 hours of day and 12 hours of night (based on the movement of stars “decans”). Beginning in the New Kingdom (1500 B.C.), there is evidence that sundials, shadow clocks, and water clocks were used to measure the passing of hours.
Ancient Egyptians used 4 sided obelisks and a T- shape sundial, situated in strategic point, to tell the time as the sun was passing by. They were also the first ones in creating portable sundials. Time was calculated depending on the length of the shadow.
However, there is no evidence that the Egyptians tracked minutes or seconds. A year had 3 seasons and 5 holy days, 1 month had 3 weeks of 10 days each. The Lunar calendar was used for religious activities, the sun or civil calendar was used for everyday activities.
By the middle of the
Old Kingdom (2450 B.C.) Egyptians had developed a civil calendar composed of 12 months of 30 days each, divided into 3 seasons:Inundation (Akhet), Emergence (Peret), and Harvest (Shemu) of 4 months each, with five epagomenal days added at the end of the year.
Old Kingdom (2450 B.C.) Egyptians had developed a civil calendar composed of 12 months of 30 days each, divided into 3 seasons:Inundation (Akhet), Emergence (Peret), and Harvest (Shemu) of 4 months each, with five epagomenal days added at the end of the year.
Official dates were expressed according to this system, as a specific day within a specific month of a season (e.g., Day 15, Month 3 of Akhet). It is likely that New Year’s Day originally was associated with the heliacal rising of the brightest star in the night sky, Sopdet. I’m
In Egypt, this star reemerged after a 70-day stay beneath the horizon at about the same time as the first signs of the annual Nile flood that brought life. Since a true astronomical year has 365.25+ days, the Egyptian civil calendar fell back by a quarter day or so each year.
Some Egyptian festivals were scheduled according to the lunar cycle than tied to specific days in the civil calendar, and some double dates, have led scholars to posit an early luni-stellar calendar that would have operated alongside the civil calendar. J. Kamring, N. Marie.
