Posted February 9th, 2013, 02:09 PM
Last edited by FlyerTalker; February 9th, 2013 at 02:15 PM
The ATL-BCN non-stop is seasonal. It has only now been removed from the October schedule. A number of routes are losing their "summer" status earlier this year - most from late October back to mid-September.
As for it being only 1/4 "booked", unless you have access to airline inventory, you don't know that. I'm assuming you are using a seat map which is VERY inaccurate at showing loads.
Best time to buy: When you see a price you can live with. There is no "magic time", "magic date", "magic interval" or any such hokum.
For those who are curious about schedule changes, and not just for DL, you may find this website interesting, if geeky: Airline Route