Comment by ggm

Date. Date and time. Approximate date. Conjectural dates like "before 1932" or "Easter, but maybe before 1905"

Date of capture/scan vs date of scanned artefact.

It's a minefield.

Adhoc methods like "month zero" or "nonce time" suck too.

Then there's how Google, Apple and Microsoft don't agree if file acquired EXIF data is mutable. Side cars. Search terms. Modified in system or by an API? Another minefield.

Post edit. Same or different image? Perceptual hash fine but can I track source image by a field in edited image?