Copy reformatted date to custom field
I am scanning a lot of quite old film for which I can only guess at the date taken. Aperture import puts the timestamp of the scan in the date field. I have created a custom field "Date Shot". I will manually enter the date as yyyy-mm-dd (perhaps only year). I would like to be able to sort all of my photos by Date Shot. This means copying and reformatting the timestamp for all of my digital photos (in certain projects) into Date Shot.
It looks quite possible using AppleScript. I have done lots of programming, but know nothing about that language. Just quickly reviewed the Aperture 3 AppleScript document.
I would appreciate any ideas or code to use as a start for this effort. I assume one can pick out the date components and reformat using printf-type commands.