Yes I was a bit imprecise and wandered about with my various examples... a photon doesn't experience time but an observers in a reference frame inertial-ish to the microwave background and generally far away from a gravity well will have a consistent agreement of when a photon is emitted, when it crosses an event horizon, and perhaps what happens to that photon as the black hole evolves. From the photon's experience it is emitted and absorbed at the same instance, my questions about duration are about how an external observer would assign times and locations to events for that photon.