thanks for a (some kind of) evening
1. An expression of gratitude said to someone when leaving some social occasion they hosted in the evening. Words like "lovely," "nice," "wonderful," etc., are used before "evening." Thanks for a super evening, guys. What a fantastic party! That was a delicious dinner, and you make for wonderful company. Thanks for a lovely evening all around.
2. An expression of gratitude said to someone after spending an evening with them, as on a date. Thanks for a wonderful evening, Jenny. I'd really like to see you again sometime.