I just checked my flight scheduled for 6AM today and found out the first leg of my UA flight from OAK-BUF through ORD has been pushed back over 1-1/2 hrs, which will cause me to miss my connection. End result, I will not make a business meeting/dinner since I will be arriving 4 hrs later in BUF. Do I have any recourse to either force UA to find me another flight (through UA or partner airline) or receive any type of compensation? If I take a later flight with UA, am I better off calling reservations and making the change now, or make the changes when I get there? Thanks.