On January 7, 1949, NBC station WNBQ commercially debuted its television broadcast schedule on channel 5, with a minimum of two hours of programming per day. April 15, 1956, is remembered as "C-Day" at WMAQ-TV, and was described by Broadcasting-Telecasting magazine as "a daring breakthrough the black-and-white curtain." With Mayor Richard J. Daley looking on, NBC President David Sarnoff operated the controls as Channel 5 became the world's first all-color TV station as "Wide, Wide World" was broadcast to 110 NBC-TV affiliated stations across the country. The color conversion project cost more than $1.25 million with advertising costing $175,000. On "C-Day", three skywriting planes flew over the city, trailing streams of red, green and blue smoke.