My flight schedule has changed, and I will be arriving at the destination airport about 6 hours later than my original plan.

I tried to modify the pick-up time, but Thrifty rate has already gone up more than $100.

How long would Thrifty hold my reservation? Would they wait like 6 or 7 hours? If I call on the same day and there was a delay, would they try to charge me more money?

Thanks.