I don't know if this is possible with air traffic but I have been using marine traffic sites for a few years and I found that some of them have an archive. This actually allow you to go back to a specific date.

I started using the Marine traffic when I first heard about pedo island and stumbled across a site. The first one I used showed yachts at a nearby island but that site was too limited and don't show any details. The next time I remembered to get in a different site and that one had all the bells and whistles but I believe they had an archive but you had to pay for the "upgrade" and I was broke.

Anywoo I am gonna start doing the plane fag thing. It's new to me but I can't wait to get started