Message for Roberts1892, don't panic!! I also wear a suit for work 50+ hours/week and have travelled with celebrity on board the Century, I wore a smart dark business suit on formal nights because I could not justify the expense of a dinner suit. I am 44 and found 60% of people on formal nights dressed the same as me, on informal nights a nice pair of trousers and short sleeve shirt (open necked, no tie!) were the order of the day, the Americans at my table dressed the same. It was mainly the groups of 60+ age group that chose to dress formally all the time.
Beware of the comment about it being chilly, this might apply if you are under an air con outlet, but we were on the upper level of the main restaurant and I had to leave early rather than pass out with the heat. Fine for all the ladies in nice lacy evening dresses but not us guys trussed up like oven ready chickens in shirt and ties.
Take your new wife for 'casual dining' in the restuarant at the rear of the ship, this must be booked with guest services and is very intimate with superb personal attention, me and my wife really enjoyed this and will be doing it again in November on the Summit.
Most of all enjoy it, it's a great way to holiday!
:uk