I am assuming that you are U.S. based and have an appointment at a U.S. Passport Agency and not a U.S. Post Office. I have got every U.S. passport issued on the same day, the first one in less than 20 minutes. It has progressively taken longer or has become harder.

1986- May: I got my very first passport in less than twenty minutes. I walked into the office in Philadelphia, with all my documents, photographs and a copy of the ticket. They didn't look at the ticket at all. NO extra fee for expedited service.

Jan-1987: I got my second passport from Washington, D.C. We took the old passport and the tickets. It took a few hours. No extra fee for expedited service.

Dec 2006: For the third passport they charged expedited fee and still did not want to issue it on the same day-- Dec 6th. I had barely 10 days left for the trip and I had to apply for a visa also. They still suggested that I come back the following day. Some begging and pleading convinced them to oblige.