The show began broadcasting from 10 Rockefeller Plaza in 1952. The studio was on street level with huge windows around which passers-by would gather to appear on TV. After a few years, the show moved to a more traditional studio in 30 Rockefeller Plaza, the worldwide headquarters of NBC. In 1994, the show relocated to that same glass-enclosed studio, 1-A.
When the show started in 1952, it was seen only in the Eastern and Central time zones, broadcasting three hours a morning but seen for only two hours in each time zone. Later, it aired live for five hours a morning, but it was seen for only two hours in each time zone. Since 1958, the show is tape-delayed for the different time zones. For many years it was a two-hour program from seven to nine ET, until NBC expanded it to three hours (7-10 A.M. Eastern Time/Pacific Time; 6-9 A.M. Central Time/Mountain Time) on October 2, 2000. In 2007, NBC expanded the show to four hours.