So... United cancelled/changed one of my flights over the 4th of July, giving me an additional 3 hr layover in Chicago and delaying my arrival from 8AM to Noon.

Called Customer Service, and got someone in India - recently I'd gotten US based agents, so I was a bit surprised to be speaking to India.

Asked the agent to change my ticket to the previous day since the schedule change made my travel plans so inconvenient.

No questions asked, no fees, no hassle, no debate - she changed my ticket for me. Sweet!!!