we were in November and AK stayed opened late enough to see Pandora in the dark and it was truly stunning! to really maximize experience, we waited until about 5min to closing to get in line to FoP (regular standby line). the line wasn't bad - maybe 30 min? then when we were done, the park was almost empty and we slowly walked through Pandora on the way out and it was one of my favorite memories from DW.
But others are correct - watch your timing for other attractions - anything with animals will likely close around 5pm or so - Safari, walking trails, etc. Last Lion King show was also 5pm. Don't ignore Dinoland - the playground there was my kids' (8 and 4) almost favorite thing in all of DW. They spent a solid hour there. I think it might be closed now but should reopen by the fall. I was also surprised that my 4yo LOVED Expedition Everest! that was his favorite ride in all of DW! he didn't love FoP as the glasses were too big and kept falling off so it was a bit of a mess of a ride for him and for me.
My kids also loved the Affection Station and spent at least half hour chasing after pigs and goats and petting them.
Finally, they both did Explorers Badges and didn't finish all of them.
For us it was a full day and we didn't get to do everything. We did use
Genie+ and it was helpful, especially for things like Lion King show where people lined up an hour in advance or otherwise you don't get a seat and we needed to be sure to catch the last show.
If just focusing on rides, you can do it in half day, but if taking it all in and going at slower kids' pace, it's easily a full day. There's also excellent food, so we'd rather take the time to have lunch and dinner there than elsewhere.