I'd suggest OP wait at least until next Mon (DL "Schedule Change Saturdays" take a couple days to settle out) ... last week I got a notification for a 1 Oct flight, and a week ago for 13 Sep and 2 Oct flights; luckily all were minor and didn't require me to actually do anything
as usual, do some research and have your acceptable options ready to give to the phone agent (typically DL won't complain about +/- a day, or to/from a nearby airport)