No idea about Uhr but clock most likely dates back to the great wave of clocktower building, 14th century, when timekeeping became mainstream. In Low Saxon “[It is] one o’clock” is “[Dat is] Klock een”, also klock == bell as well as clock, “Uhr” and “hour” both come from French, ultimately PIE *yōr-ā which is also responsible for year. Clock apparently comes from Celtic, onomatopoetic formation.
No idea about Uhr but clock most likely dates back to the great wave of clocktower building, 14th century, when timekeeping became mainstream. In Low Saxon “[It is] one o’clock” is “[Dat is] Klock een”, also klock == bell as well as clock, “Uhr” and “hour” both come from French, ultimately PIE *yōr-ā which is also responsible for year. Clock apparently comes from Celtic, onomatopoetic formation.