Leonardo da Vinci wrote about a clock design that was more accurate than the clocks of his time in his book, Codex Atlanticus. He did not invent the clock, but he did make improvements to the current design. Da Vinci’s clock had two separate mechanisms for both minutes and hours, comprised of weights, gears, and harnesses. There was also a dial that kept track of changing moon phases, and he incorporated diamonds and rocks in the design. The biggest change from the conventional clock of the time was that da Vinci utilized springs instead of weights to operate his clock. However, his design was never brought to fruition. By the 17th century, pendulums were incorporated into clock design and brought new innovation to traditional clock design.

Sources:

“Clock.” Leonardo Da Vinci's Clock Invention, 2008, http://www.da-vinci-inventions.com/clock.aspx.

“Clock.” LEONARDO DA VINCI'S INVENTIONS AND IDEAS, www.leonardo-davinci-inventions.weebly.com/clock.html.

Image Source : Leonardo da Vinci (https://commons.wikimedia.org/wiki/File:Leonardo_da_Vinci_dial_of_Venus.jpg), "Leonardo da Vinci dial of Venus", marked as public domain, more details on Wikimedia Commons: https://commons.wikimedia.org/wiki/Template:PD-old.