How did the ancient chinese measure time?

The Chinese has a saying, “Time is money, but you cannot buy it with money.” The sentence distinctively expresses the time concept of the Chinese. Yet before the invention of clock and watch in the modern times, how did the Chinese measure time?

The oldest time-keeping machine is called gnomon, solarium or sundial, the basic principle of which is to measure the time through the direction and projection of the sun. It is commonly called sun clock.

i think it would be reparing roads