Block programming or television block is a strategy of broadcast programming and radio

Radio

Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...

 programmers. Block programming occurs when the television network

Television network

A television network is a telecommunications network for distribution of television program content, whereby a central operation provides programming to many television stations or pay TV providers. Until the mid-1980s, television programming in most countries of the world was dominated by a small...

 schedules similar television program

Television program

A television program , also called television show, is a segment of content which is intended to be broadcast on television. It may be a one-time production or part of a periodically recurring series...

s back-to-back. The concept is to provide similar programming to keep the viewers. Radio stations use it consistently: they program the same type of music for long periods of time. A notable example of block programming was NBC

NBC

The National Broadcasting Company is an American commercial broadcasting television network and former radio network headquartered in the GE Building in New York City's Rockefeller Center with additional major offices near Los Angeles and in Chicago...

's "Must-See-TV"

Must See TV

"Must See TV" is an advertising slogan used by the NBC television network to brand its prime time blocks of sitcoms during the 1990s, and most often applied to the network's Thursday night lineup, which featured such popular sitcoms as The Cosby Show, Family Ties, Cheers, Night Court, A Different...

 Thursday evening, which included 2 hours of sitcoms and 1 hour of ER

ER (TV series)

ER is an American medical drama television series created by novelist Michael Crichton that aired on NBC from September 19, 1994 to April 2, 2009. It was produced by Constant c Productions and Amblin Entertainment, in association with Warner Bros. Television...

, Channel 4

Channel 4

Channel 4 is a British public-service television broadcaster which began working on 2 November 1982. Although largely commercially self-funded, it is ultimately publicly owned; originally a subsidiary of the Independent Broadcasting Authority , the station is now owned and operated by the Channel...

's "T4" program which often ran sitcoms like Friends back-to-back for an hour or more..

Block programming in radio also refers to programming content that appeals to various demographics in time blocks, usually corresponding to the top or bottom of the hour or the quarters. For example various musical genres might be featured; a country music hour; a 3 hour afternoon of jazz or a 4 hour Saturday night 70's disco show.

Generally speaking block programming is anathema to modern competitive commercial radio. It is counter to the brand maxim to "be one thing" and is confusing to listeners. Therefore most music based stations will generally stick with one genre or sub-genre of music. Block programming of this nature is alive and well on outlets like public radio (NPR, BBC, CBC) and in multicultural radio serving broad ethnic and cultural audiences.

Notable television program blocks

Popular television program blocks include:

• Nick at Nite
  Nick at Nite
  Nick at Nite is the nighttime Cable network that broadcasts over the channel space of Nickelodeon on Sundays from 8.p.m.-7.am., Monday through Fridays from 9 p.m.-7 a.m. and Saturdays from 10 p.m.-6 a.m. . Though it shares channel space with Nickelodeon, A.C. Nielsen Co...
  
  
• Nick Jr.
• TEENick
• SNICK
  SNICK
  SNICK was a two-hour programming block on the American cable television network Nickelodeon, geared toward general audiences, that ran from August 15, 1992 until August 28, 2004. It was aired on Saturdays starting at 8 p.m and ending at 10 p.m. ET. In 2004, SNICK was revamped as the Saturday night...
  
  
• The '90s Are All That
  The '90s Are All That
  The '90s Are All That is a programming block that airs on TeenNick. The block shows requested Nickelodeon shows from the 1990s, airing in a two-hour block running every night from midnight to 2 a.m., with an encore from 2 to 4 a.m...
  
  
• USA Up All Night
  USA Up All Night
  USA Up All Night is an American cable television series that aired weekly on Friday and Saturday nights on the USA Network. The show aired from 1989 to 1998.-Synopsis:...
  
  
• The Disney Afternoon
  The Disney Afternoon
  The Disney Afternoon was a created-for-syndication two-hour television programming block which aired from September 10, 1990, until Fall 1999. At that time, it was taken out of syndication, and a new Disney weekday afternoon block was started on UPN. The Disney Afternoon was produced by The Walt...
  
  
• Jetix
  Jetix
  Jetix was a worldwide children's television programming brand owned by The Walt Disney Company. The Jetix brand was used for blocks and channels featuring action-related and adventure-related live-action and animated programming. It was also what Disney eventually turned Fox Kids into...
  
  
• Toonami
  Toonami
  Toonami was a registered trademark of Cartoon Network, used initially for action-oriented programming blocks on Cartoon Network television channels worldwide, mostly showing American cartoons and Japanese anime, originating in the United States on March 17, 1997 and ended on September 20, 2008.The...
  
  
• Adult Swim
  Adult Swim
  Adult Swim is an adult-oriented Cable network that shares channel space with Cartoon Network from 9:00 pm until 6:00 am ET/PT in the United States, and broadcasts in countries such as Australia and New Zealand...
  
  
• One Saturday Morning
• TGIF
  TGIF (ABC)
  TGIF was the name of an American family-friendly prime time television programming block on the ABC network. The name comes from the initials of the popular phrase "Thank God It's Friday"...
  
  
• PBS Kids
  PBS Kids
  PBS Kids is the brand for children's programming aired by the Public Broadcasting Service in the United States founded in 1993. As with all PBS programming, PBS Kids programming is non-commercial. It is aimed at children ages 2 to 10...
  
  /PBS Kids GO!
  PBS Kids GO!
  PBS Kids GO! is an educational television brand used by PBS for programs intended for older children, rather than the original PBS Kids. It is primarily broadcast on PBS stations during the afternoons...
  
  
• The CW4Kids
  The CW4Kids
  The CW4Kids is a Saturday morning cartoon block on The CW Television Network that premiered on May 24, 2008 in the place of Kids' WB...
  
  
• Fox Kids
  Fox Kids
  Fox Kids was the Fox Broadcasting Company's American children's programming division and brand name from September 8, 1990 until September 7, 2002. It was owned by Fox Television Entertainment airing programming on Monday–Friday afternoons and Saturday mornings.Depending on the show, the...
  
  
• ABC Kids

Some program blocks become so popular, they are later transformed to 24 hour channels. Current channels that were once program blocks include TeenNick

TeenNick

TeenNick, formerly The N, is an American television network aimed at the teenage market. TeenNick is owned by the MTV Networks subsidiary, Viacom. The channel was originally known as The N from its April 1, 2002 launch until September 28, 2009....

 and Nick Jr.

Nick Jr.

Nick Jr. was a programming block on the Nickelodeon television channel, seen on Nickelodeon weekday mornings. It was aimed at a preschool-age audience ages 6 and under. On September 28, 2009, Nick Jr. became its own official channel, replacing Noggin...

 both of which are former program blocks on Nickelodeon

Nickelodeon (TV channel)

Nickelodeon, often simply called Nick and originally named Pinwheel, is an American children's channel owned by MTV Networks, a subsidiary of Viacom International. The channel is primarily aimed at children ages 7–17, with the exception of their weekday morning program block aimed at preschoolers...

; and Boomerang

Boomerang (TV channel)

Boomerang is a 24-hour American cable television channel owned by Turner Broadcasting System, a division of Time Warner. Boomerang specializes in reruns of animated programming from Time Warner's extensive archives, including pre-1986 MGM, Hanna-Barbera, Cartoon Network, DePatie-Freleng Enterprises...

, which was once a program block on Cartoon Network

Cartoon Network

Cartoon Network is a name of television channels worldwide created by Turner Broadcasting which used to primarily show animated programming. The channel began broadcasting on October 1, 1992 in the United States....

. Also, TV Land

TV Land

TV Land is an American cable television network launched on April 29, 1996. It is owned by MTV Networks, a division of Viacom, which also owns Paramount Pictures, and networks such as MTV and Nickelodeon...

 airs older shows that were once aired on sister channel Nickelodeon's Nick at Nite program block.
Disney Junior

Disney Junior

Disney Junior is a current program block on Disney Channel and an upcoming American basic cable and satellite television network intended to replace SOAPnet in February 2012. It began airing on February 14, 2011, replacing Playhouse Disney....

is scheduled to become a full-time channel in January 2012.