Patty,
I can't speak for United, but last trip I learned a new term in phraseology thanks to Jet Blue and check-ins.
Ask not what time you can check in, but what time you can check in AND CHECK YOUR BAGS.
We called JB before our flight home last trip and asked exactly that thinking we were covering all our bases - "what is the earliest time we can check in for our 2:00ish departure?" We got to the airport at the time we were told only to find out we could check in but had to hold onto our bags until much later and then, to make matters worse, they kept pushing up the time. After sitting in the downstairs check-in lounge for over an hour with all our luggage we were finally allowed to check our bags. Just a slight variation in words can make a huge difference in the realities. <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" /> <img src="http://www.traveltalkonline.com/forums/images/graemlins/handshake.gif" alt="" />