In principle, composite nouns are written together. It can be written for better legibility or for highlighting individual components but also with hyphen.
Personally, I would write it without a dash, as it is possible to read it so well and, in my opinion, nothing has to be highlighted.
Serial evening is correct in any case, but in such composites it is also possible to set illustrative hyphens. But this is mainly intended for longer, unclear composites. Personally, I find it unnecessary here, if not unsightly. I don't think it's wrong.
Both are possible, but the hyphen is used when it is to be clarified that it is two independent and individually independent nouns which together make sense.
In principle, composite nouns are written together. It can be written for better legibility or for highlighting individual components but also with hyphen.
Personally, I would write it without a dash, as it is possible to read it so well and, in my opinion, nothing has to be highlighted.
See also here in D21 and D22: https://www.duden.de/language/language rules/binding
Serial evening is correct in any case, but in such composites it is also possible to set illustrative hyphens. But this is mainly intended for longer, unclear composites. Personally, I find it unnecessary here, if not unsightly. I don't think it's wrong.
https://dict.leo.org/grammmatik/english/legal/regulations/remark.html?lang=de#id=4.1.3.1.a
Both are possible, but the hyphen is used when it is to be clarified that it is two independent and individually independent nouns which together make sense.
In your example, I would use "serial night".