Adjust date/time pictures and movies on Photos

Photos.app can only modify the photos' date inside its own database and it does not export the modified date out. Sometimes Photos.app ignores correct EXIF date in jpegs exported from Lightroom.

I edit all metadata (EXIF dates, image dates, image names, locations, captions, keywords, file names) outside Photos.app with Graphic Converter (it uses exiftool). I use Photos.app only as a viewer and a 3rd backup and archive photos and videos in plain folders on external HDs.

It's easy to read metadata, extract "create date" field (using exiftool) and adjust other fields, include file date/time. But, what happens on Apple Photos? I affraid to mess índex Photos' data.

Once the photos are in the Photos Library, there is no point to modify the imported files with exiftool or other tools inside the Photos Library package. Photos is reading the exif tags only once on import and copies them to the internal database files. Later changes to the original files are not updated in Photos. You would just risk to mess up the references in the internal databases. It is hard to identify the originals anyway inside the library package, because Photos 5.0 on Catalina is renaming the originals with cryptic names.

When you use Photos's tool adjust Data&Time to correct the capture date, you can export the modified version with the new date and import it again. Then you will have the corrected date in Photos and on the original.