Prime time or primetime is the block of programming on television during the middle of the evening.

Definition

In North America, television networks feed their prime time programming in two blocks: one for the Eastern, Central, and Mountain time zones, and one for the Pacific, Alaskan, and Hawaiian time zones to their local affiliates. In Atlantic Canada (including Newfoundland) as well as Alaska and Hawaii there is no change in the interpretation or usage of "prime time" as the concept is not attached to time zones in any way.

The Prime "Times"

In the United States, the hours traditionally taken as constituting prime time are 8:00 p.m. to 11:00 p.m. Eastern and Pacific and 7:00 p.m. to 10:00 p.m. Central and Mountain Monday–Saturday.

• On Sundays, prime time begins an hour earlier, at 7:00 p.m. Eastern and Pacific and 6:00 p.m. Central and Mountain, ending at the same time as on the other six days of the week. Note that for cable networks, such as USA, TBS, and ABC Family, prime time is 8:00 p.m. to 11:00 p.m. all seven days of the week.
• With the addition of newer networks such as FOX, The CW, and MyNetworkTV, they're now considered a common prime separate from traditional prime. Common prime is 8:00 p.m. to 10:00 p.m. Eastern and Pacific and 7:00 p.m. to 9:00 p.m. Central and Mountain Monday–Saturday, beginning an hour earlier on Sundays as with traditional prime. (The CW does not have Saturday programmes in prime time, and MyNetworkTV does not have Sunday programmes.)
• Before the FCC regulated time slots prior to prime time with the now-defunct Prime Time Access Rule in the early 1970s, networks began programming at 7:30 on weeknights. For an historical look at prime time, see History of TV Prime Time

International

• Prime time in Australia is from 6:00pm to 10:30pm, following Australian Eastern Standard Time.
• Prime time in New Zealand is considered to be 7:30 to 10:30pm, but can be extended to cover the entire evening of television (6pm-11pm).
• In a great part of Latin America, prime time is considered from 6:00pm or 7:00pm to 10:00 or 11:00pm. The time slot is usually used for news, telenovelas and TV series, and special time slots are used for reality shows, with great popularity, specially in Brazil.
• In Japanese television, prime time begins traditionally at 7:00pm. This is called the golden time or golden hour in Japan, with the most popular variety programmes being on from 7:00pm to 9:00pm each day. Between 9:00pm to 11:00pm, drama programmes start.
• In Taiwan prime time starts at 8:00 in the evening. Soap series played at that time are called 8 o'clock series and are expected to have high viewer ratings.

Timeslot's relationship to radio & TV revenue

Prime time is the daypart (block of a day's programming schedule) with the most viewers and is generally where television networks and local stations reap much of their advertising revenues. The Nielsen Ratings system is explicitly designed for the optimum measurement of audience viewership by dayparts with prime time being of most interest.