MyBB Community Forums

Does anyone know if it is possible, even by a long shot, to display different forum themes at different times of the day, overriding everyone's default style as well? Thank you!

Absolutely you can do this. A plugin could make this happen even.

I looked through the plugins but didn't see one for anything like this...

I don't think there is one at the present... And convincing the database with a cron job that someone is perpetually logged in without a session / user / cookie present, is going to be one hell of a plugin..