I've sailed many times with MSC including a transatlantic crossing leaving boxing day on the opera and the dress code is invariabley the same. They will have formal evenings, informal evenings and casual. On the 19 night there were 5 formal and on an 11 night 3, so I'm guessing 4 formal for your cruise although may be 5 because of the festive period. Formal is officially evening or cocktail dress for ladies and DJ or lounge suit for men. (not everyone sticks rigidly - some make more of an effort than others - although I found more make the effort when its at festive time). You will probably find roughly half and half split between casual and informal for the rest of the cruise. Informal is meant to be cocktail dress or smarttrouser suit or equivalent for ladies and lounge suit or jacket, shirt and tie for men. casual is meant to be smart casual - officially no jeans but I've seen some of our chums from accross the pond taking casual to the extreme.IN SUMMARY, IF YOU WANT TO REALLY DRESS UP, YOU WON'T BE OUT OF PLACE BUT LIKEWISE IF YOU DON'T WANT TO GO THE WHOLE HOG, YOU WILL NOT BE THE ONLY ONE.
Thanks for your answer this really helps a lot.We have been on over 30 cruises ,(not with MSC ) never at xmas or the new year.I think we will go with 5 formal , and hope that theres no fancy dress night, IE new years eve.