Now that the age of internet is upon us, and cable and satellite have made TV a 24 hour active paradigm, viewers, readers and surfers don't necessarily sit around stuck to one location once they've finished consuming their medium of choice.
Television shows have a finite number of episodes, and when they're out, many channels either fill up the slot with new content, filler, or just play the same episodes over and over again until the new season is ready. When a book is done, there's usually a year or more until the next installment. Web content updates depending on the style of the page.
To drum up excitement and anticipation for the release of new material, popular media will have a New Content Countdown Clock which sits (not at all unobtrusively) in the corner of the screen counting down the hours and minutes until the most anticipated new material.
Particularly egregious cases (at least in the case of TV) will have the clock fixed in place so that it's even present in the corner of the screen during the commercial breaks.
May often appear — on TV at least — at the end of a Theme Week or Marathon.
- Mugglenet has done one for each of the Harry Potter books after the fourth, and all of the movies.
- Bulbapedia has had one of these for the Japanese and English-language releases of every major Pokémon game.
- TFWiki.net has done this for Transformers: Revenge of the Fallen and Dark of the Moon.
- ZeldaWiki did this for The Legend of Zelda: Skyward Sword, with separate countdowns for Europe, America, and Australia.
- Equestria Daily has them for season and episode premieres.
- Scified's Godzilla (2014) website had a countdown which ended in the phrase "The King Has Returned".
- There was a website counting down to the Gravity Falls episode "Not What He Seems". It now has a slow-loading image of an in-universe version of Punk'd, since the world didn't actually end during "Not What He Seems," as had been implied within the show and online.
- How I Met Your Mother had a now-defunct site called "Slap Countdown", counting down to the premiere of the Slapsgiving episode.
- Muppet fansite ToughPigs had countdowns for the releases of both The Muppets and Muppets Most Wanted. When The Muppets' return to television was confirmed for September 22, 2015, they put up a Kermit clock counting down to that date.
- Armageddon advertised itself with a series of large billboards with a countdown clock to the release date.
- ABC did it for V when it returned from its hiatus, and also pissed off Lost fans by showing the clock during their show.
- TNT did this with Leverage.
- USA Network had one for Burn Notice. And every new show that's premiered since.
- Disney Channel did it for, among other things, the High School Musical movies. New movies, big premieres or events or even just theme blocks can also get one. What makes it particularly annoying is that the countdown timer will be HUGE blocking out significant portions of whatever program is actually on, especially and frequently actors' faces.
- A station in Milwaukee counted down the minutes to the Super Bowl during their newscasts when the Packers were in Super Bowl XLV... from the moment they won the NFC Championship. That's 336 hours of countdown time.
- The Colbert Report website used to do this, with the implication that viewers should be literally counting down the seconds until their next chance to see wonderful, wonderful Stephen Colbert.
- During the 2007 writer's strike, NBC became absolutely obsessed with putting up solid-colored bugs with text ads above them for upcoming programs. It still happens occasionally (for high-profile premieres or the Olympic Games), but at least it's all been translucent now. Many of NBC's cable channels followed its lead with similar forms of advertising.
- AMC Runs one every Sunday to the latest episode of The Walking Dead, during the closing credits of the re-airing of the previous week's episode.
- Creator/BBC America has done countdown clocks for:
- CNN and MSNBC always do a countdown for a big presidential speech; every news channel will also count down to a "polls close" time (or in other terms, for Curbstomp Battle votes, the time they declare a winner) for an election. And during the campaign, the news channels run countdown clocks to hype up practically every single thing related to it, including debates and town halls they host, countdowns to primary/caucus coverage, and so on.
- ABC had one counting down to the Royal Wedding of William and Kate.
- At the end of the preceding episode of Stargate SG-1, Sky1 did this for the premiere of Stargate Atlantis. Since they forewent an ad break between the two, and the countdown only occurred over the end credits, nobody minded too much.
- Taylor Swift tweeted one in the runup to her album Red. First it was daily tweets at the 10-day mark (with an Instagram of the relevant number of something or other — six flowers, perhaps, or seven band members' feet), and then she started making or retweeting hourly updates with one day to go.
- ESPN has done this occasionally with a small strip above their ticker, for things such as the College Football Playoff National Championship, and NBA Finals games on ABC. The latest iteration of their ticker now has a large area off to the side, filled with a cycling slideshow of ads for upcoming events and their app (used in parallel with the aforementioned strip).
- MLB Network put up a somewhat intrusive box above their ticker to advertise the next game they're airing (often with team logos or pictures of the starters). They eventually made a streamlined version that fits into their ticker instead — an example NFL Network also follows for certain content as well.
- Comedy Central had one when Futurama was Uncancelled.
- The Mantis-Eye Experiment, a noted fansite of The Venture Bros., featured a countdown clock to the first episode of Season 3 once the schedule was announced.
- Cartoon Network does this religiously. Among the shows given this treatment:
- Ben 10: Alien Force
- The Clone Wars
- The Clone Wars: Secrets Revealed
- The premiere of The Looney Tunes Show
- The season premiere of Scooby-Doo! Mystery Incorporated.
- The premiere of Firebreather.
- Both Fionna and Cake specials.
- The Total Drama World Tour premiere and finale. The final five seconds of the countdown even continued after the show.
- Green Lantern: The Animated Series has one for the season proper starting in an episode of Ben 10: Ultimate Alien
- The premiere of Uncle Grandpa.
- The 2014 Powerpuff Girls special.
- The midseason finale for season 1 of Steven Universe: "Mirror Gem" and "Ocean Gem".
- Several special episodes of Teen Titans Go!, with the one for the 200th episode starting two weeks before.
- Generally with a massive counter taking up a quarter of the screen. Who wanted to see that other show, anyway...
- Nickelodeon has done this about as much as CN, such as for the long-awaited final season of Avatar: The Last Airbender (at least in US markets ...the episodes had aired and the DVDs gone onsale elsewhere). They've also counted down to special events such as the Kids Choice Awards.
- Nicktoons has done it for the anticipated first episode of Dragon Ball Z Kai.
- Nicktoons flashed an occasional one to remind viewers of the new Merchandise-Driven Zevo-3 series in the days leading up to its October 2010 premiere.
- The now-defunct WBKids did the website variation for the premiere of Loonatics.
- The Hub had a countdown for, among other things, every new episode of Transformers Prime.
- My Little Pony: Friendship Is Magic has this webpage.
- Homestuck had a quasi-example with its End of Act 5 Animation Bump - Andrew Hussie added a progress bar measured in percentage which he continually updated over the months spent working on it, and partway through issued a target release date of October 25 2011. Plenty of countdown clocks ensued on fansites.
- Life In A Day did this on their YouTube channel.
- Shops will often do this for when a big product is coming out, such as a video game - often they'll keep a constant clock in the window and just change the images whenever it needs to.
- ESPN's main buildings will have these for major sports events, such as the Olympics or the World Cup.
- When Y2K mania was happening, manufacturers sold clocks three years in advance counting down to the new millennium which blinked on and off once the moment came. Thankfully most of them functioned as regular clocks after that date.
- New Alice and Bob
Tonight at 9:00!