How long should I keep the pop-up open after rain?

It doesn't take long to dry out the surface. The gotcha is when water is trapped in folds and along seams. THAT can take a while, days even, if you don't go out and ensure everything gets exposed to the air.

I have left it popped up for three days in the warm weather of Arkansas, only to take it down and have water drip on me from where the vinyl roof was touching the underside of the hard roof, trapping water. That's disappointing.