Dave Price writes in with a quirk of Photos related to exporting images he’s edited:
In the new Mac Photos app, I found that the only way to export photos and keep the original date that the photo was shot is to export the original. So after carefully cropping and adjusting the many editing options, how can I export the edited photo without losing the creation date?
It’s a strange omission from Photos for OS X, though you could think of it as philosophical in nature: Apple only exports a newly created version, rather than one that’s the original, modified. That’s probably too existential for software, however.