The Bobsleigh Season
Essentially the bobsleigh season starts as soon as temperatures are cold enough for a track to be able to cost-effectively make ice. While a track could in theory be maintained year round, the chemicals (primarily ammonia) needed to cool the track would cost far too much for it to be financially viable. Therefor the bobsleigh season runs from late October until early March. There are no southern hemisphere tracks.
The world Cup is an 8 race event that operates in a similar fashion to the F1 circuit. All eight races are in different locations around the world. they run from November until the end of February, with a break for Christmas. This usually means that every practice and subsequent race in one location will last a week, with more time allowed for travel if it is across continents.
Simultaneously there are two other circuits that operate, the North American Cup, and the Europe Cap. Using the same 8 race principle, these competitions only exist in their respective continents, and are less prestigious than the world cup. Here is where a lot of drivers will start their careers, or supplement their world cup campaign with extra runs.
At the end of each season there is a large World Championships. Here the top 25 sleds ranked across the World, North American, and Europe cup, will compete in one race. This is usually held at the start of the race, and its finish signals the end of the season. The World Championships are replaced by the Olympics in the calendar every four years.