Question

........one of the most important earlier clock used these days also​

Answer 1

Answer:

Sandclock is the answer I guess

Answer 2

Answer:

sundial

Explanation:

A sundial is a device that tells the time of day when there is sunlight by the apparent position of the Sun in the sky. In the narrowest sense of the word, it consists of a flat plate (the dial) and a gnomon, which casts a shadow onto the dial.