I'm thinking about ways of representing time and timelines in RDF. My angle is from the biographic / genealogical areas. I want to be able represent 'episodes' in a person's life, e.g. from 1876 to 1881 my great grandmother lived in Risca (a small town in Wales) and in 1880 my great-great grandfather was killed in a mining disaster . What's the best way to represent these so that I can answer questions like where was my great-great grandfather living when he died? Other questions involve knowing when people got married, especially when they marry several times and change their surnames.

I can see a few different approaches: wrapping events up in episode groups or explicitly labelling each event with start and end dates. Another way I'm thinking more about is to attach the date information to the actual triples in the store. Then I can take a snapshot of the 'world' at any point in time and only triples that are valid for that date would be present. What other approaches are there?