How was it determined that a day would have 24 hours

Humanity's relationship with the measurement of time began even before the first written word. This is the reason why it is difficult for us to actually investigate the many units of measurement of time.

Since some of the units derived from astronomical phenomena seem fairly easy to define, it can be assumed that they have been used independently by many different cultures around the world.

It is a matter of the apparent motion of the Sun with respect to the Earth to measure the duration of a day or a year. As for the measurement of months, it is done according to the phases of the moon.

However, there are some measurements of time that do not clearly relate to any astronomical phenomenon, and two examples are the week and the hour.

Egyptian hieroglyphs are one of the oldest written traditions. This gives us new information about the origins of the clock. It appears to have originated in North Africa and the Middle East region and was adopted in Europe before spreading throughout the world in modern times.

Time in Ancient Egypt

The inscriptions in the Pyramids of Egypt, written before 2400 BC, are the earliest known writings of ancient Egypt. Among them is the word 'wnwt', pronounced roughly wenut, and a hieroglyph associated with a star. It seems that 'wnwt' is related to night.

To understand why the word 'wnwt' was translated 'hour', you have to travel to the city of Asyut. There, the inside of the rectangular wooden lids of the 2,000 BC coffins were sometimes decorated with astronomical tables or the directions of the stars.

This table had columns representing 10-day periods of the year. The Egyptian civil calendar consisted of 12 months, each consisting of three 10-day 'weeks', followed by five-day festivals.

Each column contains the names of 12 stars, making 12 rows. The entire table represents the changes in the sky throughout the year, like a modern star map.

Those 12 stars are the first systematic division of the night into 12 temporal regions, each ruled by a star. However, the word wnwt is never attached to these coffin star tablets.