The camera won't deface your photos by scrawling a string of numbers across them. However the date and time (and a lot more) are stored with every picture in its EXIF metadata. Any photo editing program should be able to display this data and overlay it onto the photo.
Answers & Comments
Try to use the following software TimeToPhoto to add dates from EXIF to photos automatically:
http://avpsoft.com/products/timetophoto/
Regards
The camera won't deface your photos by scrawling a string of numbers across them. However the date and time (and a lot more) are stored with every picture in its EXIF metadata. Any photo editing program should be able to display this data and overlay it onto the photo.