The longest I ever worked on a contract was 2 years, the shortest was probably 2 hours. Most projects were 1-3 months. At the company I'm thinking of, they kept a public list of people who were "on the bench", which meant they'd finished a contract, and the company didn't have another one for them yet. In sports, being on the bench sort of implies that you can't cut it, but 99% of the time that's not how it was.