I've mentioned it before, but my strange experience with clocks on the show was in A STITCH IN CRIME. For a long while I thought that the object Columbo slams down on Dr. Mayfield's desk during that angry moment was that attractive clock you see him winding early on. And that put me off a lot more than the angry moment itself, which was called for. So I was really relieved when I realized it was the paperweight instead.

In the Greenhouse Jungle, Jarvis makes a point of setting the dashboard car clock back (on the E-type Jag) to disguise the time of the fake "abduction" .

Doesn't fool Columbo of course!