Now that it’s time for Daylight Saving Time, most Americans, Europeans and others around the world will observe the annual shift, switching the clock forward one hour when it strikes 2 a.m. Spring Daylight Saving Time will add an extra hour of daylight at the end of the day. Though many people think the custom helps farmers or saves energy, it’s really an economic measure, Michael Downing, author of Spring Forward: The Annual Madness of Daylight Saving Time, tells TIME. Contrary to another popular opinion, Daylight Saving Time is not federally mandated.