This diagram shows the knowledge about time. How did humans first begin to measure time, and what is time? The first clock to measure time is the sun dial, which was almost 4,000 years old. Using the sun's shadow, Egyptians created a way to measure time. Then, created a water clock, which was over 3,000 years old. Humans needed something more accurate. Want to know more about time and clock, click this diagram to learn more about time now!