A fork for the time-zone database?

I like reading WW2 autobiographies, and I remember one escort commander complaining about a ship under his command ... iirc the Captain operated "ship's time" which was GMT+2. Seeing as the rest of the flotilla kept local time on the transatlantic run, the Commander was moaning that he had to remember what the time was on this ship, as he'd get reactions like "can't a chap have his afternoon nap in peace?" ... early in the morning!

Cheers,
Wol