Strange clock question
 

What is the white hand?

A simple placekeeper? An alarm that no longer works?

Yep just a placekeeper for timing your travels.

And here I thought it was a jammed second-hand.

If you do a search, many, many, many think it's a non-working second hand...

Even seen clocks for sale here "second hand doesn't work".

Not an alarm either.

Concept of elapsed time marker eludes many even after an explanation.

HAHA Same concept as a rotating dial on a wrist watch. Set the 60 to current time and watch the time fly......

Actually...if driving fast enough, time will appear to stand still... ;)

Wow.......never imagined that there was that much mystery.

S.

I thought it was the 12 hour hand...I set it and when the other two hands get back around to the white hand, I know it's time to stop driving around and go home. :D

You push in the control and turn the hand to whatever you want, its a place keeper for timing something.

An Irish gang from Brooklyn in the early 20th Century.

placekeepers were very common in airplanes in the past. Since a clock in an airplane has a timing purpose, as well as a "what time is it", it's installed to be a simple way of noting how many minutes until or past. It's made to be easy to set while you are usually too busy, or wearing gloves in the old days, to set a complicated stopwatch.