Chronometers Are Wound And Compared
As I was scurrying around the house this morning resetting clocks, I thought back to the boats and how we handled the concepts of time changes there. (The ones I was thinking of were the "planned" time changes, not the urban legend of the QM who would satisfy the pre-underway requirement to ensure chronometers were wound and compared by going into Radio, writing down the accurate time off the Cesium Beam on a 3" x 5", then going through the boat setting all clocks to that time.)
As the boat transitted east and west, you would have a time change every day or two (depending on how far from the equator you were), and I think most boats did those on the midwatch, which was nice if you were heading east (the watch would be shorter by an hour) but not so nice on the westbound legs. Where it got interesting was for the PacFleet boats approaching the International Date Line, since you had to figure out when you were going to make the big switch. The "westbound crossing" scenario had a couple of key issues involved:
An obvious way to do it was just to go (for example) from 2359:59 on February 13th, and two seconds later it would be 0000:01 on February 15th. This made it convenient from a log-package preparation standpoint, but it had a couple of drawbacks -- when you were looking through log packages months later, there might be questions from, say, the ORSE Board, about where your log packages were from February 14th. This wasn't a big deal. The biggest problem I saw was what to do for crewmembers who's birthdays were on February 14th (in this example). Did you really want to take their birthday away? When I did this transit on Topeka back in '92, we actually checked, and there was no one on board with that "problem"; on Stennis in '00, however, there were over 100 people who "lost their birthday". (My preference would have been to have at least 1 hour of the day in question, and switch from 0100 on one day to 0000 the next, since the Date Line is really a 23 hour advance, with the normal time zone change included.)
For the eastbound Date Line crossing, we just ended up labelling the log packages "A" and "B" after the date, and had a lot of "Longest Day" jokes...
How did your boats handle it?