The Business Cycle Dating Committee of the National Bureau of Economic Research provides a historical chronology of business cycle turning points. We investigate three central aspects of this chronology. How skillful is the Dating Committee when classifying economic activity into expansions and recessions? Which indices of economic conditions best capture the current but unobservable state of the business cycle? And which indicators best predict future turning points, and at what horizons? We answer each of these questions in detail using methods specifically designed to assess classification ability. In the process, we clarify several important features of the business cycle. (JEL C82, E32)