Who thought of the concept of time?

It may have begun a lot earlier with the Sumerians, but the first people we can prove timekeeping with is the Egyptians. Around 3500 B.C, with the building of the obelisks, Egypt kept time with the moving shadows. Sometime later, approximately 1500 B.C. the sundial came into use. Then, 900 years later, they invented the "mehket", a device used to measure the hours during the night by using the movement of the stars.

Then came the Greek water clocks, somewhere in the 600's B.C., which marked the hours and were improved upon by the Romans. After that, during the medieval period, mechanical clocks were invented and they measured the hour and quarter hour. Galileo added the pendulum, and Huygens perfected it to be accurate to within one minute a day.

Since I love clocks and own a large number of them, I took the "time" (LOL) to learn the history of them. Below is a site I found for the origin of the increments of time. Hope it helps.

The original of 60 seconds to a minute and 60 minutes to an hour come from the Babylonians, who used a base 60 numeric system. The 24 hour day takes its origins from the same idea, the Babylonians divided the day in half and determined the each day should have 12 hours of daylight and 12 hours of darkness, even this meant that the length of time in a second, minute and hour would vary. Presumably 12 hours, because like 60, it was divisible by 2, 3, 4 and 6, and 12 hours seemed more feasible than 60 hours to divide daylight and darkness into.

I believe it was the Babylonians who started in this way. 60 was a convenient number (and still is) because it can be exactly divided by 2, 3, 4, 5, 6 and their various products.

The ancient saints from pre-historic times devised the concept of time by observing the days with the moon and the period of one revolution of the earth around the sun.

sumerians , hebrews, babylonians, egyptians and also mayan civilization