Should we still use the sun and moon to tell time?

Genesis 14 And God said, “Let there be lights in the vault of the sky to separate the day from the night, and let them serve as signs to mark sacred times, and days and years,

6:96 …He makes the night for rest and tranquility, and the Sun and Moon for telling time. Such is His judgment and ordering, the Exalted in Power, the Knower of all things.