Fantasy Novel. World with 2 suns, very strict rules. But when both suns are down everything goes.

[Grafula]

I read this fantasy novel about 35 years ago.

It is about a world with two suns. So it very rarely gets dark. They have very strong morals and very strict rules. I. e. eating is shameful. And they only eat behind a kind of screen that covers their face.

But when both suns set at at the same time and it gets dark, everything goes. All rules are off.

Can't remember anything else. Don't know if author is female or male. Don't remember cover.

Thanks for any help.

[Andrés]

sounds like nightfall by Isaac Asimov, there is the short story and the novelization

[Kris]

Nightfall and Nightfall and Other Stories by Isaac Asimov for Andres' suggestion.

[Peter]

It's not Nightfall. The society on that planet had never experienced darkness before, so they didn't have rules for it.

[Grafula]

Thanks, but no, I'm sure it wasn't by Asimov.

[Lobstergirl, au gratin]

For adults, YA, or children?

[Grafula]

Adults

[Lobstergirl, au gratin]

Grafula, are you still looking for this or did you find it?

[Lobstergirl, au gratin]

No response; moving to Abandoned.

[Lobstergirl, au gratin]

Grafula is still looking and wrote:

"This is a fantasy book or novel.
It is set in a world with two moons. There is nearly always at least one moon in the night sky.
Eating is shameful and not done in public. If people eat they cover their mouth with a screen of some sort.
It is a very ordered world.
BUT when no moon is in the night sky all hell breaks loose."