jetsetter

I wonder if US has changed its computer programming so it prompts the agent to charge a pax if a Move Up is attempted more than 6 hours in advance?

Also remember the airport agents can do anything with a ticket, they have the permissions in the system to essentially re-evalidate any ticket as an irregular operation. ZSometimes you'll see INVOL in the endorsement box when this is done. They can also change the status of a flight coupon sometimes without reissuing the ticket.

I think also when the system prompts the agent to charge if they press shiuft-F8 it brings up a menu where they can override the fee.

Your mileage may vary as some agents feel completely comfortable overriding the system and putting in place any policy they see fit. Other agents fear that big brother is watching them and they fear or say they fear anyway if they just enter in an INVOL over-ride for whatever you want. But I know at all the airlines, its not just US, an agent can do pretty much withg in reason what they see fit with a ticket and a lot of them don't feel they will be disciplined.

A same day change to an earlier or later flight should be "reasonable," for a preferred member, and this is what I would expect to have as a sort of unwritten or informal policy at the airport despite any rules that come from corporate.

Also whatever you do, don't call, because they will note your reservation that you were advised say that changes cannot be made more than 6 hours. The best procedure is for you to just show up at the ticket counter or the gate.