Umbra solis non aeris

This short phrase comes from a sundial.  "Umbra solis non aeris" means "the shadow of the sun not of the  bronze."

Tempus fugit irreparablile

Amici fures temporum is far from being the only Latin proverb about time.  Perhaps the best known one of all is tempus fugit irreparabile, which means time flees irretrievably.

Tempus fugit irreparabile and similar sentiments are often inscribed in Latin on sundials.