how many formal nights on a 6 day cruise. i need to know so i know what to pack. thanks so much

Just one "optional" formal night on cruises a week long or less, and two "optional" formal nights on longer cruises.

You won't need a tux. Not even a suit or sports coat. I've been on the Spirit and the dress code is optional. I wear only slacks, not jeans, and a shirt with a collar. Usually a Hawaiian type shirt. I saw one tux on the NCL Sun cruise that I took earlier this month. I ate in the Main Dining Rooms except for one night. Used the buffet that night. The Spirit has a large and very good buffet if you want to eat there. Lots of places to eat. When you want, where you want and with who you want to eat with. No assigned seats or times! Great.