You created your account on May 19, 2011 (shows up below your name on a desktop computer).
The jazzfanz.com website and message board was created in 2004, I think.
@Jason would know the date for sure. I became a mod in Jan 2005, and I think the board was less than a year old at the time (but I could be wrong.) The board was created after Jason and others got frustrated with the realgm board that many of us had been using prior to that. There was a substantial exodus from realgm to jazzfanz at that time. I think I myself registered for jazzfanz about 3 weeks after it was founded. (I waited for a few weeks to see if the posters I liked most were going to bail on realgm or not. They bailed.) I can't recall which people who are still here joined at that time, but speak up if you did! I think there are maybe 10 of us still around. Anyone who's been here since 2004 is truly old school.
As the last three posters have alluded to, there was a massive board crash in 2010. All data was lost. Everyone had to re-register for the site. So anyone who has a May 2010 or Jun 2010 join dates (again, visibly on the desktop site) was undoubtedly around prior to the Great Board Crash of 2010, and in my opinion also deserves to be called old school even if they aren't quite as old school as the 2003-2004 originals.