Tempus fugit is actually the Latin for “Time flees” and not “Time flies”. You may not think there’s much of a difference but rest assured the difference is quite important. “To flee” is to run away quickly usually from something or some sort of danger. “To fly” is simply to run away quickly. The difference may be in the nuance but that is surely the point. A ripple starts off as a tiny point in the ocean, the wings of a butterfly… etc. Nuances are what make different languages. Semantic ripples are what distinguish a superlative translation from an average one. Yes, “Time flies” does sound better than “Time flees”, but does that mean that the former is a better translation than the latter?