How to keep the original date when exporting photos from Apple Photos app?

You may want to upgrade your Mac to macOS 14.2 Sonoma.

Since the upgrade to Sonoma, my exported photos are exported with the capture date as the file creation date.

For example, this is a picture of a very old painting, where I have adjusted the date to the day the picture has beeb painted - the exported image file has the changed date as the file creation date: ("erstellt" means creation date in German).

"Export unmodified original" used to keep the original file creation date, but it does no longer work, when we are using iCloud Photos. The syncing with iCloud and downloading the originals from iCloud is already changing the file creation date of the originals and they will be exported with the date they have been downloaded from iCloud.

This has been fixed in Sonoma.

I don't use iCloud Photos but I believe that the internal "real" metadata is preserved when you use the "export unmodified originals" option. I guess it is the file system dates (file creation & modification dates that are often confused to be metadata) that some macOS versions might change when moving files around.