My earliest ride was in 2002 - December 2nd. Great conditions too! That was my second year riding, after the '01-'02 riding season, which was terrible here in the east. The '02-'03 riding season is probably the best I've ever seen. I rode 3300 miles, mostly on great conditions. If I wasn't in grad school I might've got a lot more miles too.
The season didn't end until mid-March, which is late for around here.
I remember guys riding on Thanksgiving in 2000. Cold, early start to the season that year. But I wasn't riding then.