I was successful at having my flight moved a day earlier a few years ago and I went from traveling on a cheap day to a very, very expensive day and on my first call too. Be nice, be honest - you don't need to make something up - just say with the schedule change, I think flight #### and flight #### on the day earlier would work better into my schedule. Is it possible for me to switch to those? If they say no, just thank them, say you will think about your options and HUCA.