OK, for many of us, December is the first month that really means the start of full-time winter weather. November was pretty laid back this year, at least in many parts of the US. Heck, I live in Michigan and I rode home in shorts the last 3 days. But they're promising 7 inches of snow on Dec 1, and I for one mounted my Nokians last night.
The challenge is to set a goal to commute every day by bike. Some people allow a few emergency/sick days. You may have to exclude certain days of the week for errands or what-have-you. It's really up to you and what you feel is achievable, but don't sell yourself short. Aim high.
This is totally up to you. You can start any time. There is no prize apart from pride, and no consequences for failure other than your own disappointment. This is all about setting your own goals and reaching them. And a little public bragging when you do.
October commuting challenge
November commuting challenge
I'll start a separate thread each month throughout the winter. Take one day, one week, one month at a time, and you'll rack up more days than you probably thought possible!