Not sure if this is the right forum to put this in, but here goes. I was successfully able to change the DateTime Stamp of the photo, but the original date appears on the photo...a setting on the camera. Is there a way to remove / fix THAT date/time?
If you are talking about a time stamp on the image itself, then you must use an image editor (not a metadata editor) to change it. I recommend something like Photoshop -- I'd do this with the clone stamp.
- Phil