It was completed in 410 days and President Herbert Hoover turned on the lights on May 1 , 1931 . Each held the title for less than a year , as the Empire State Building surpassed them upon its completion , just 410 days after construction commenced . The building was officially opened on May 1 , 1931 in dramatic fashion , when United States President Herbert Hoover turned on the building 's lights with the push of a button from Washington , D.C. Coincidentally , the first use of tower lights atop the Empire State Building , the following year , was for the purpose of signaling the victory of Franklin D. Roosevelt over Hoover in the presidential election of November 1932 .