My join date is also messed up. I think there was a server issue back in the day and everyone lost their real join date. Some asked for it to be changed back and some like me were too lazy to care.
You'll notice at the bottom of the page that the software that runs this board is vBulletin. In September 04, Shrink was running a piece-of-shit software that crashed all the time so he opted to run the board on the new vBulletin software.
When the new software was installed it reset everyone's join date to the current month. Those who wished to have their real join date showing emailed the mods and the mods changed it for them.