Premise: The 2007–08 Tour de Ski was the 2nd edition of the Tour de Ski and took place from 28 December 2007 until 6 January 2008. The race kicked off in Nové Město, the Czech Republic, and finished in Val di Fiemme, Italy, ten days later. It featured 8 top international cross-country skiing competitions, of which two were sprint events.
Hypothesis: The 2007–08 Tour de Ski lasted for 2 years