Many U.S. workers don't use all their vacation time

Think you don't have enough vacation time? A new study validates that Americans are an overworked bunch.

A Harris Interactive study found more than 50 percent of American workers do not use all of their time off. In fact, most of them leave 11 days unused every year.

U.S. law does not require companies to give their employees paid vacation time.

In the United Kingdom, companies must give workers 28 days off every year. Germany and Japan require employers give employees at least 20 days of vacation.