Set Exif Dates on Scanned Image - 23 September 2012 - images
Scanned in a few old pictures recently, and found that some of the tools I had written for organizing and synching them would benefit from (at least approximate) date meta-data.
I found a nice universal tool to modify EXIF data: ExifToool by Phil harvey. It even has a mac installable dmg download.
Here's a nice shortcut for setting all 3 common date fields in a JPEG image.
# show original dates (there are none!)
$ exiftool -alldates test.jpg
# set the dates
$ exiftool "-alldates=1968:05:16 05:00:00" test.jpg
# show updated dates (there are 3!)
$ exiftool -alldates test.jpg
Date/Time Original : 1968:05:16 00:00:00
Create Date : 1968:05:16 00:00:00
Modify Date : 1968:05:16 00:00:00