Was on a 14 day to Hawaii & back, Oct 2019, Halloween fell on the 3rd to last day, the entire 28th-31st days on the way back were all Halloween. Big, huge costume contest, pumpkins, trick-or-treat, etc, lots of it. The entire 2 weeks was decorated, but the first half of the cruise was all Hawaiian, 2nd half was all Halloween. It was fun. Lots of cabin decorations for sure.