Today (U.S. TV program) debuted, it was seen live only in the Eastern and Central time zones, broadcasting for three hours each morning but seen for only two hours in each time zone. Since 1958, "Today" has been tape-delayed for the five other U.S. time zones (Central, Mountain, Pacific, Alaska and Hawaii–Aleutian). Partly to accommodate host Dave Garroway's declining health, the program ceased live broadcasts in the summer of 1958, opting instead to broadcast an edition taped the previous afternoon. The experiment, which drew criticism from many sides, ended when John Chancellor replaced Garroway in July 1961. "Today" was a two-hour program for many
Prime Time Access Rule hour of prime time (7:00–8:00 p.m. Eastern Time and Pacific Time, 6:00–7:00 p.m. Central, Mountain, Alaska and Hawaii–Aleutian Time) as the "prime access hour". By the early 1980s, the PTAR had introduced a policy amendment prohibiting stations in the 50 television markets with the highest prime time viewership from broadcasting more than three hours of network programming during the four-hour "prime time" block. Stations had to find original programming to fill during the "prime time" fraction. However, the rule exempted certain types of programming, such as overruns of live sports events, special news, documentary and children's programming, and certain sports