I will apologize in advance if this has been covered before. I am thinking that a commentary is in order for the timeline of the sinking of the Titanic and the statement in the first episode "It is 16th April 1912 and the Titanic has gone down". The point of this post is to solicit opinions and suggestions.
The point is, it could be argued that it could have been any of the 15th, 16th or 17th. What is clear is that Fellowes has condensed the timeline for dramatic effect, the actual timeline was considerably more complex.
The fact that the telegraph message comes in during the middle of the night gives the impression that it is still the 15th. This of course is impossible since the Titanic went down at 2:20AM local time, which would have been 5:20AM GMT, or for purposes of this discussion, GT or Grantham Time. The fact that the Titanic had sunk could not have been relayed to anyone prior to the arrival of the Carpathia, approximately two hours later (7:00AM GT), and the last lifeboat was not picked up until about noon GT.
The first scene at Downton is when Daisy knocks on the doors of the other maids saying that it is 6:00 AM. At that point on the 15th the Titanic had sunk, but the Carpathia had not arrived. Obviously the fate of the Titanic could not have appeared in morning newspapers of the 15th. The 16th, as used by the S1E1 page, however has its own problems.
First, there is another 24 hours in which some news, especially to someone as connected as the Crawleys, would start getting out. At least that the Titanic had encountered some sort of a problem, so it would not have come as a complete surprise when it appeared in the paper.
The second and bigger problem is the actual stories that appeared in the papers on the 16th durring the fog of the disaster which had many of the facts wrong, such as headlines in the Daily Mail which included "Titanic Sunk". "No Lives Lost", and "All Passengers Taken Off". One of the articles goes on to say that the Titanic is being towed by the Virginian to Halifax.
The magnitude of the disaster really did not start to appear in the papers until the 17th. By this time, news certainly would have started to leak out and thus not come as a complete surprise in reading the papers.
Adding to the problem is how quickly the fate of James and Patrick was learned. There were very few confirmed dead prior to the Carpathia arriving in New York on the 18th and limited information getting out as to the survivors, since the presumed dead could only be estimated by subtracting off the known survivors from the passenger lists. Adding to the problem was that maintaining passenger records was not particularly strict in those days, so there were at least 100 passengers that were either listed as being on the Titanic and were not, or conversely not listed on the Titanic but were.
So in summary, I am not saying the presumption that the first episode occurs on April 16th is wrong, I am just saying that the actual timeline is much more complicated and was understandably simplified to tell the story. Thus something in the way of a clarification would seem to be appropriate.