Some how, I am given the impression that higher-end camera tends to leave out the date print found on our old photos in the cabinets. My Contax T3 has that as a hefty $200 option to replace the back cover with one with a date imprint feature! That's wicked.
Moving on to the Nikon D90, I could not locate anything that resembles the above feature until a few minutes ago! Its classified as "Print set (DPOF)" under the playback menu of the camera. Upon selecting the photo(s) you wish to print, you are given the option to print both data and date onto the picture you so chosen.
Well, at least this feature comes without the need to shelf out more cash like my older compacts.