What night is formal night on a 3-Day cruise?
Also, do they allow nice dress pants (for kids) on formal night?
Since there is no formal night on 3-Day cruise, men don't have to dress in suit/sport coat & tie?
Nope. Seems most or all of the men wear polo-style shirts or similar. Don't waste the space in your luggage packing anything dressy. The 3-night DCL cruise is just about as casual as you can get.