Metadata for dates prior to 1/1/1970 not stable

[lezrob]

When I change the date in metadata from whatever was on a scan of old photos (usually nothing), if the date of the photo is prior to 1/1/1970, the metadata will change to 1/1/1970 or 12/31/1969 at the stroke of midnight if I do any operations in APhoto 2.5 prior to exporting. If I do all my editing then change the date, then immediately export, it seems to export the date correctly. Windows 11, Affinity Photo 2.5, not using hardware acceleration. 

[NathanC]

Welcome to the forums @lezrob,

This is something that we have had logged previously with the developers however we have been advised this isn't something that will be fixed due to the way the 'date shot'/'created at' fields are represented internally for legacy reasons.

It would be better to put the date shot in a different field such as description if it predates 01/01/1970.

[- S -]

Putting "Date Taken" metadata in a different field such as Description is not a good idea, as nothing will read it there.

This date needs to be in designated IPTC, EXIF or XMP "Date Taken" metadata fields (such as EXIF DateTimeOriginal), so that other applications (and Windows File Explorer) can read it and will know what it is.  This will also allow image viewers to display the images in the correct chronological order by "Date Taken" (not Date Created or Date Modified file timestamps, which will be incorrect) and ensure they appear before other images taken after 1970-01-01.

To do this, the dates need to be added using alternative software that is not restricted by the 32-bit 1970 Epoch time and is therefore capable of handling a greater date range. 

Unfortunately, I can't really advise which applications support this.  I use Exiftool with 64-bit Perl as I don't just write dates, but sometimes convert them, however I think from Exiftool 12.88 (2024-07-11), the Exiftool site now offers a 64-bit version of Exiftool that comes with Strawberry Perl included – but I haven't used it yet.

The issue with Exiftool though is the dates need to be added using the command line, which is not something that's user-friendly for the vast majority of people.  However, for those who are OK with scripting, it will allow adding "Date Taken" metadata to an entire folder of images at once and even allow sorting by filename and then sequentially incrementing the timestamp too, so the photos retain the correct chronological order for that date.  I.E.

1940:12:25 00:01:00
1940:12:25 00:01:01
1940:12:25 00:01:02
etc.

[lezrob]

Thanks guys.  I am happy that I'm not nuts.  After reading this, I have been using Windows 11 to change the date, although that is a PITA.  Irfanview is supposed to do it but it also seems to be unstable for the really old dates, and has to be a jpeg.