Our 24-hour day is based on the Egyptian division of day and night
. The division of the hour into 60 minutes and the minutes into 60 seconds came from the Babylonians. The Egyptians combined the Babylonian system with their own count of 24 hours in a day. To mark the passage of the daylight hours, they made shadow clocks. The first shadow clocks were simply blocks of wood with a pointer. As the sun seemed to move across the sky, the shadow made by the pointer changed its length and position. Eventually the Egyptians made shadow clocks with 12 periods of time to divide the day. The shadow clocks were also called sundials.