Uncertain time ranges for photos

[kaj]

Sometimes the exact moment a picture is taken is not certain, but there exists a range (which may be in a specific day or or a wider range of several years. There should be a way to handle that.

Representation

Should the range be two columns of the photos table or a separate table? Should the existing date column be used as one end of the range (probably the end)? Or should it be used for when an analog photo was digitized? Should a photo from a digital camera (known timestamp) have a null range? Or should it it have three timestaps (start-of-range, end-of-range and digitized) that have the same value?

Should all the dates be nullable? Maybe at least the end of the range can be non-null, and get the value from the file date of the image or the date when the table row is created? Maybe the start of range can default to when the first photograph was taken? Or the first artwork (rock carving)? Or just the earliest date the Timestamp type can represent?

Presentation

One way (the main way?) of finding images is to browse by date. But where should an image be shown if it has a time range instead of a specific instant? Should year / month / day pages have a section for images that may have been taken in that interval?