jeremiah was there for the first session, wasn't he? I think he was. That means we started playing on Labor Day Weekend.
To be more specific about Archon's entrance, Archonus joined the group by demanding custody of Jaine Rilmore, AKA Jaine Rhynn, shortly after Justice kicked the crap out Ta'ra Miagee (who, at the time, she thought was Lord Miagee). Before he could gain cutody of the wanted criminal, Lord Miagee requested a private audience with the young caravan leader, and a few of you found out that she apparently shared some sort of quality with Lord Miagee's former Emperor.
Does that help?