Past Its Prime?

We went on a road trip this week - and of course, we hoped to play poker to help cover our expenses.

But our timing was bad, because we were in the southern Illinois area on a Tuesday night.  Harrah's Metropolis only opens its poker room there four nights a week - Thursdays through Sundays.

Does this say something about poker as a whole?  Is it declining in popularity?  Or are there good and bad nights for business, even at casinos?