During the winter months in the northern United States, mechanics may work fewer than 40 hours a week, because the amount of repair and service work declines when lawnmowers, motorboats, and motorcycles are not in use. Many mechanics work only during the busy spring and summer seasons. However, many schedule time-consuming engine overhauls or work on snowmobiles and snowblowers during winter downtime. Mechanics may work considerably more than 40 hours a week when demand is strong.