We live in an era where watches are almost purely just an aesthetic choice. Basically everyone has a smart device in their pocket that is able to tell them the time.
What if, instead of a watch, you brought along a cat. Their pupils will go completely round at night and turn into slits during the day. With a but of practice, you'll be able to use cats to tell the exact time of day.
Imagine this scenario; Your friend asks you what time it is. You being an absolute mad lad, reach into your coat and pull out a cat. You then stare deeply into the cat's eyes and divinate the time of day.