of the mean solar day, based on the measure of the sun's transit along the celestial equator rather than along the ecliptic.
This was finally abandoned due to the minor slowing caused by the Earth's tidal deceleration by the Moon.
By the time of ), the priests at Karnak were using water clocks to determine the hours.
These were filled to the brim at sunset and the hour determined by comparing the water level against one of its twelve gauges, one for each month of the year.
The modern ke is now used to count quarter-hours, rather than a separate unit.