Roy, the time business has been argued loud and long. The British inquiry found that Titanic time was 3hr 10min behind GMT. I happen to agree with that, for reasons set out in my book.
The most likely alternative, favoured by some, is that the difference was 2hr 58min behind GMT. This is based on the idea that Titanic's clocks were set to agree with her last noon position, in accordance with an old nautical convention.
Both positions have their backers. The evidence either way is not very conclusive. Neither the British nor the US inquiry took much interest in the matter.
To quote myself,"It is submitted that a time difference of 1hr 50 min ahead of NYT, or 3hr 10min behind GMT, best fits the rather limited evidence. It is also submitted that the exact difference is of very little consequence, except to
Captain Lord's defenders, and those whose hobby it it to make the straight crooked and the plain places rough."
The arrival time in New York was meant to be in the early hours of Wednesday 17 April. This fitted in with US immigration and customs authorities. However, the conditions were very favourable, Titanic was running very well and from the position at which she hit the berg she could have arrived at the Ambrose lightship at the entrance to New York harbor by about 10 or 11pm on Tuesday 16 April, assuming a speed of about 22 knots, which she had been doing for more than a day.
Ironically, she would probably not have succeeded in doing this, even in the absence of icebergs, as there was fog on the course and she would have been forced to slow.