In Greek mythology, Chronos (χρονος in Greek) in pre-Socratic philosophical works is said to be the personification of time. He emerged from the primordial Chaos. He is often mythologically confused with the Titan Cronus (κρονος in Greek).
He is often depicted as an elderly, gray-haired man with a long beard. His name actually means "Time" , and is alternatively spelled Khronos, Chronos, Chronus (Latin version). Some of the current English words which show a tie to khronos/chronos and the attachment to time are chronology, chronic, and chronicle.
In astronomy, the planet we now call Saturn because of Roman influence was called Khronos by the Greeks. It was the outermost planet god/deity, and was considered the seventh of the seven heavenly objects that are visible with the naked eye. Given that it had the longest observable repeatable period in the sky, which is currently around 30 years, it was thought to be the keeper of time, or Father Time, since no other objects had been seen or recorded to have a longer period. That is why it is often depicted as an elderly man with a long gray beard, as mentioned above.
Greek gods | Time and fate gods
Chronos | Chronos | Chronos | Chronas | Chronos | クロノス (時間の神) | Chronos | Chronos