Is there a one-time use (disposable) camera with a date stamp. If
there is, where can I buy one in Philadelphia, PA? Any major retail
store or camera store would work.

Somehow I doubt that this exists. Such a feature would add to the cost
of the camera, and I doubt that there would be sufficient demand for
the product at the increased price. Disposable cameras are
"no-frills." A time/date stamp is a frill.