Izzit rude to...leave early??

[HotelMinion]

I'd to get some opinion on this. Recently, I've joined a group of people who meet with common interests, and such. It's really fun, and I always enjoy myself. (sometimes it's awkward, but whatever. They're pretty introverted, as am I. eheh)
But since I work overnights, I have to leave at 10 pm cuz of work. I already asked if they could move it earlier and they did, for a short while, then back to late evenings because that's when everyone else gets off of work. -_- Oh well. I don't really mind, since I'm not one to 'hang around' doing nothing. But whenever I leave before anyone else does, everyone there gives me weird looks that make me think I'm being rude to leave early.
So is it rude to leave parties early? Just wondering. I don't think so, so why are they giving me weird looks.

[OneMoreTime]

Since you have to go to work, no I don't think it's rude. Do they know you are leaving early because of work?

[taxguykarl]

I've left meetings early...ironically I received the most criticism for leaving one with no discernible agenda other than: sit in a sauna and watch the presiding staffer argue with a consultant.

[MoonCat]

As long as they know why you're leaving early, it's not rude and it shouldn't be a problem. This is a social group, not a mandatory work meeting, so they shouldn't make an issue of it.