I have a very confusing problem with dates on photos. Tried searching, and found various similar issues since MC11 (I am at MC27.0.77) but none that quite gave success in my case.
I use a different system (Synology Photos) to tag a bunch of old, scanned photos (facial recognition, correct dates, kyewords/tags etc). When a file has been updated with new Keywords, MC imports this just fine automatically after a few seconds. But dates are a big problem. I have hundreds of old paper photos that I have scanned during the past 10 years or so. I have used MC General/Date to specify date taken on these. But Synology Photos does not interpret the date info from MC correctly for quite a lot of the files (all?). So I ended up using Synology Photos to change the date tag, since I know this writes a new Date Taken EXIF info. I can see this in Windows explorer. For some files, MC imports this new date as "General/Date", but for other files, this does not happen. What then most often happens is that, since the file now has a new "Date Modified", MC interprets this as "General/Date" and ignores the Date Taken in the file.
I then removed General/Date and General/Album Date in MC and ran Library Tools/Update Library (from tags) for a few test files. For one image (EXIF Date taken: July 1 1986) the new MC General/Date became 01.01.1899(!).
Could anyone care to explain what I do wrong here, or if there is some bug. Please...