KJM58,
While I have to admit that I'm with Gene on this topic, I can understand that others may want this ability.
The camera, itself, cannot perform this function but a quick Google search of "add date to photo" comes up with many software possibilities -- at least one free, others for minimal cost -- where you can date-stamp the photos once they have been transferred to disk from the camera.
Here are a few:
PhotoUtil
Image Transformer 1.2
SignRobot 1.1
Batch Photo 1.0
Dick