That is definitely enough time to hit the major attractions at DAK. But, sadly, you will miss some of the detail of the park and smaller exhibits. For example, you can breeze through the Maharajah Jungle Trek is about 20 minutes. But you could easily spend an hour or more walking through the attraction soaking it all in. We usually plan two partial days at DAK, but we take long trips so we can afford the extra day.
Just a couple of suggestions. 12-7 is a lot of time, but the park will be its busiest between 12 and 3. That's OK because a lot of visitors leave around 3. However, make sure you are not visiting on DAK's EMH evening. If you do, you will get the worst of two worlds: (1) you will have missed the slower morning hours and (2) it will be busy between 12 and 3, and instead of slowing up after 3, the EMH people will start to roll in for their evening touring keeping it busy all day.
Don't miss the afternoon parade; it is one of the best at WDW. It starts at 4:00.
If you are looking for a character breakfast, try Donald's Breakfasaurus right in DAK. Good food and character interaction.
When you get into the park, if Expedition Everest is open, go get fastpasses immediately. They will be running out pretty early.