I'm new to New York, relatively speaking, so perhaps this is common knowledge, but... what's the deal with the museums?

The Met is closed on mondays, except holiday Mondays. I understand being open on the holidays (more people around wanting to do something), but why close on other Mondays. Is it for cleaning purposes? Can they not hire a cleaning crew that works sometime during the sixteen hours a day they aren't open?

They close at 5:30pm on weeknights, which also makes no sense to me. I live about a mile from the met. It's an easy and enjoyable walk through very nice neighborhoods with cool architecture. I'd love to wander over there after I get done with work and spend a few hours checking the place out. Yet the only time they're open late is on Friday and Saturday nights, when I am most likely to have other plans (although I guess admitting that I am likely to choose barhopping over museum crawling isn't terribly classy).

MOMA is even weirder. They close entirely on Tuesdays, and otherwise operate under similar hours to the Met.

I'm sure there are museums in this city that are open at night (in fact, Chris's wife works for one that we visited -- a cool place dedicated to Tibetian/Himalayan art), and I don't think I'll have a hard time finding them. I'm just wondering why two of the biggest, best known museums in New York have such weird hours of operation.

EDUCATE ME!