As far as I can tell, this can not be done, so may be a feature request.
Today I ended my Giganews account. I run it for a couple of months for catch-up, then use the free service from my ISP, repeating the cycle when needed
On Disabing the giganews servers, and activating the ISP's server, NewsBin prompty went and downloaded over 50 million headers, i.e. those since it was last on that server.
What I would like to do is have the new server start from the current day, or 'x' days past. Not only would this save downloading well over 20GB of headers, it would also save a lot of time on downloading headers i have seen before.
Is this possible ?