Hello T&O,
Yes there was indeed time differences between the two ships. It is a very sore point of controversy between researchers.
I was trying to avoid this but I'll explain as best I can.
At Noon on April 14, Titanic was 2 hour 58 minutes SLOW of GMT. At the same moment, Californian was 3 hours 10 minutes SLOW of GMT. There was therefore a 12 minute difference between ship-board times. It follows that at 11-40pm on Californian that night, the equivalent GMT was 15d 02-50am and the time on board Titanic would be 11-52am. The recorded time of impact was 12 minutes earlier at 11-40 ship time.
If Titanic had not changed her clocks before impact, the ship which stopped near Californian would still have been approaching her for another 12 minutes after Titanic had hit the iceberg.
Titanic had planned to set her clocks back a total of 47 minutes that night. 24 minutes at Midnight April 14 and the remaining 23 minutes during the following 6 hours. If she had made the first 24 minute change before impact then the difference between her clocks and GMT would have increased to 3 hours 22 minutes. This would still give a GMT to ship time difference between the two ships of 12 minutes. Thus when it was 15d 02-50am on Californian. it was 11-28pm on board Titanic and she still had 12 minutes to run before impact. The ship near Californian would have been stopped for 12 minutes before then.
However, this is all academic because Captain Rostron of
Carpathia sent a message to his owners that Titanic had hit the iceberg at 15d 3-00am GMT.
The reported ship-board time of impact was 11-40pm April 14. This gives a Titanic ship to GMT time difference of 3 hours 20 minutes, not the 2 hours 58 minutes as was at Noon April 14. It follows that the first adjustment had been made BEFORE impact and that when it was 11-40pm on board Californian...15d 02-50am GMT, it was 11-28pm on board Titanic and she had another 12 minutes to run before she hit the iceberg.
Whatever way you look at the problem; because of the 24 minute planned time adjustment, Titanic ship time was either 12 minutes FAST of Californian ship time or 12 minutes SLOW of it. I believe it was the latter.
Jim C.