Typically around Mid October to late March. Winters have been erratic the past few years, but last year was the coldest in a while and we burned about 4 cords. We don't burn all day, only when we're home - and when we're home, the wood stove is always burning. We have electric heat, and a fairly efficient and modern heat pump, but the wood is a plenty and I just love the smell, comfort and rustic ambiance of burning wood.
We run a lot of electrical appliances from multiple beer fridges, reptile heaters and pumps for our four scaley critters, so burning wood saves big time on the electrical heating cost. I think our largest electric bill last winter was $140.