Who invented the first clock ?

One possibility could be this guy!


Clepsydras became more complicated, even to the inclusion of gearing in about 270BC by Greek inventor Ctesibius of Alexandria. Eventually, a weight falling under the force of gravity was substituted for the flow of water in time devices, anticipating the mechanical clock.

Britannica.com has clepsydras dating from ast least the 15th C BCE, probably earlier.

The answer to this question may depend on the meaning of the word "clock".