If you have an appointment in the morning, you'll have an antibiotic right away. If no appointment (first time visits are sometimes scheduled a month down the road), tell them you have an ear infection -- that may raise the priority so you get in.
If you can't get to see a regular physician (or his/her nurse practitioner is just as good), go to a walk-in clinic. They're more expensive with long wait sometimes, but they see everyone that day.
It's a good idea to get the initial visit with the doctor of your choice done so next time you can call and they see you that day.
All that said... I hope you get an antibiotic tomorrow. Seems like within 24 hours the ear should be feeling ok. I'd go for the hike.
