thanks for your contribution.

You are right, there is a possibility to change the time for individual pics and as a batch job. (I have clarified this in the post.) However, it doesn’t really do what you expect it to. Inside iPhoto the new time appears, but even if you checked “change original” and then have a look at the original – in my case a DNG file – it has not changed at all. Same effect if you try to export the image.

So, yes, you are right, there is a menu item, but no, it doesn’t work for the purpose of geotagging.

Klaus

One of your points is totally wrong: in your “Nine Requirements”, you state that requirement #4 (batch time adjustment) isn’t matched, “not even individually” ; I guess you’ve missed the command for it: it is located in the “Photos” menu, and there you’ll find both “Adjust Date and Time” and “Batch Change”, which do not do the exact same thing, but both allow for batch time adjustment.

Apart from that, your point on iPhoto keeping geotags for itself is unfortunately and annoyingly true >.<