Self-Adjusting Mystery Clock
RAY: The hint I gave is that Mark said he didn't have one of these when he lived in Kansas.
TOM: Yeah, I said to myself, "In your house on the Cape you have a tide clock."
RAY: Right, and the tide doesn't care whether it's Daylight Savings Time or not. The tide is the tide is the tide.
TOM: You have that clock in your kitchen, but what is a tide clock?
RAY: It tells you when it's high tide.
TOM: How does it know?
RAY: It's an analog clock that has only one hand, the hour hand. It runs slower than a normal clock because the tides don't come at six-hour intervals. High tides are anywhere from 12 hours and two minutes apart to 12 hours and 50 minutes apart.
TOM: And you certainly don't have to change it when they change all the other clocks.
[ Car Talk Puzzler ]