Since items aren't natively dated, we need to falsify their publication dates in
order to have them properly ordered by feed readers.
Separating them by any length of time will serve this purpose. But if we space
them by a week, we get two free extras:
- when adding the feed, readers will more easily be able to show a preview of
recent updates;
- this will perhaps somewhat better represent the true scope of the work at
hand, and the effort and skill which have gone into it over the years.