Been trying to work with DL and it is not going well. The first person said I could call back when I had new dates and they would rebook for no charge.

When I called back, they said it had to be a 90 minute change to be fee-free. Now they won't budge. I will cancel the flights so they are canceled before departure date and try to negotiate further. In the past, DL has been much more accommodating. They seem to like playing hardball now.