I guess I could have included ages for dead people, and theoretically it should be possible to store the DoB in the SVG and write a javascript routine to recalculate the ages and amend the SVG XML DOM each time an SVG genogram is displayed. But this is not something I am considering (don't mind at all if anyone else fancies taking it on). Could get quite complicated with all the different calendars, but there is javascript out there already to handle this. This would not be possible with the PDF format that I am working on anyway.
I have no problem that it's a snapshot, since my tree is constantly changing and is only as good as the day I publish it. I think the date is in one of the corners of the SVG chart, isn't it?
I would be happy if you could just plug in the dates, vs creating any fancy javascripts.