Each episode is supposed to take one hour of real time but in actuality, due to commercial breaks three minutes are gradually added to the timer during the show in the breaks. The last three minutes of air time are used for viewing commercials, station identification, and scenes from the next episode. Each episode general runs for around 43 minutes without commercials (slightly less in PAL territories).
Harris Yulin, who plays the recurring character of NSA director Roger Stanton in Season 2, is not credited at all in the opening or ending credits. All recurring and guest stars have to share their credits on screen with one or two other actors, but Yulin wanted to appear alone on them. Because this was not possible, he decided not to be credited at all.
At the power plant before Palmer's breakfast speech, Jack runs into old friend and Palmer staffer, Jessica Abrams. In conversation, she refers to mutual old friend Tracy Zigler, who had erroneously reported that Jack and Teri had divorced. Both characters are named after members of the production crew; Jessica Abrams is the script coordinator, and Tracy Zigler is the script supervisor.
Paul Blackthorne who plays season 3 main villain, Saunders, originally auditioned for the role of Amador, another one of the season 3 villains. After failing the audition, his agent negotiated with the producers and managed to get the role of Saunders.
During the shoot for season 4, a special six-minute segment was shot for the US version of the season 3 DVD where Jack loses his job at CTU, an antagonist of season 4 arrives in the US, and Jack has an intimate moment with his new girlfriend. This did not appear on any of the other versions of the DVD released earlier in the summer, however it does appear on the UK and German DVD release. An extended version of this segment (as stated in the commentary by director Jon Cassar) is available on the UK DVD release of season 4.
Mandy is the longest running villain to appear on the series. She made her first appearance in the first three episodes of Season 1 working for Ira Gaines, and returned in Season 2's finale for a cameo appearance where she tries to assassinate David Palmer. She returns again for the last three episodes of Season 4. Mandy was also originally intended to appear in Season 5, but was replaced by another character.
Season 4: Writer/Executive Producer Evan Katz was such a huge fan of Australian music duo Grant McLennan and Robert Forster of the band The Go-Betweens that he named the sinister corporation McLennan-Forster after them.
Partway through season 2, Kiefer Sutherland injured his leg while exiting his trailer, so a small scene was written in where Jack Bauer must pull a piece of shrapnel from his leg after a plane crash to explain Sutherland's limp.
During season two shooting, Elisha Cuthbert was bitten by the mountain lion who menaced her in one of the plotlines. Before shooting the scene the animal trainer suggested she "meet" the mountain lion before shooting, when she went to pet the mountain lion it bit her hand. She was taken to the hospital, treated for puncture wounds and was given a tetanus shot.
Season 3. Whenever Jack goes into the holding facility which houses Salazar, at some point, he is picked up by security cameras. The legend on the video surveillance monitor at the guards' station shows constantly that he is being taped by camera #24.
Season 3. A Mexican airplane appears briefly during Salazar and Bauer's landing on Mexican ground. The logo on its side reads "Aeromexicana". The name is comprised of Mexico's two largest airlines "Aeromexico" and "Mexicana".
Gabriel Macht was originally offered the role of Jack's partner Chase Edmunds but the producers were so impressed by James Badge Dale's audition they offered him the role and promised Gabriel Macht a significant role in the next season. This never materialized.
Jack Bauer has a Bachelor's Degree in English Literature from UCLA and a Master's Degree in Criminology and Law from UC Berkeley. Kim Bauer has an Associate's Degree in Computer Programming from Santa Monica College. President Palmer has a Bachelor's Degree in Political Economy from Georgetown University, and a Juris Doctorate from the University of Maryland School of Law. Tony Almeida has a Bachelor's Degree in Engineering and Computer Science from San Diego State University and a Master's Degree in Computer Science from Stanford University. Michelle Dessler has a Bachelor's Degree in Computer Science from UC Davis. Sherry Palmer has a Bachelor's Degree in Sociology from Georgetown University.
In Season 3, Stephen Saunders demands that the President reveal some classified information, which would then be sent to him via a website. The website he mentioned is SylviaImports.com. This site was actually registered by Rodney Charters, the show's director of photography (and director of a couple of second season episodes). It contains the following text message: "A Big Thank-you from the crew of 24 (2001). Thanks for watching, we love making it for you, and yes, we did get picked up for Season 4."
In Seasons 1 & 6 there is a CTU character called Milo Pressman (played by Eric Balfour). There was a character called Milo Pressman, who ran a scrapyard in the Stephen King's story "The Body" in his book "Different Season's". The story was later made into the film Stand by Me (1986) in which Kiefer Sutherland starred.
In the Day 5 episode 4:00 p.m.-5:00 p.m. Audrey identifies herself to the secretary as Jane Espenson. Jane Espenson is a writer who had previously worked with David Fury (one of 24's producers), on several Joss Whedon shows.
In the fifth episode of the fourth season, Debbie's cell phone rang with a valid California phone number on the caller ID. Many fans noticed this and called the number, Some callers heard a voice mail message telling them that they called the 24 prop phone and to leave a message. Others spoke with various people, including Production Designer Joseph A. Hodges and stars Kim Raver (Audrey Raines) and Carlos Bernard (Tony Almeida). Hodges later stated in an interview that director Jon Cassar came up with the idea for the "Fan Phone" because the two of them often got bored scouting new shooting locations and wanted a chance to interact with the audience. Hodges indicated they received around 80,000 calls on the line in the first week. There is also a valid California cell phone number on S03E03, Chase's cell number appears in Jack's cell.
In Season 4, while Mandy (Mia Kirshner) has Tony Almeida (Carlos Bernard) held hostage, she goes to her neighbors' apartment and one of them calls her "Rothenberg." This is the same last name as C.T.U. agent Shari Rothenberg (Kate Mara) in Season 5.
The Season 6 plotline involving hostiles taking over CTU headquarters and Jack's nephew eluding them by crawling through air ducts almost exactly parallels a plotline from 24: The Game (2006), except that in the game it was Jack's daughter Kim eluding the terrorists.
Jack's last name came from a character we've seen in La Femme Nikita (1997) (Peter Bauer, #1.06). The famous split screen we see in 24 was used on La Femme Nikita #1.03 and Jack's motto "whatever it takes" is said by Michael and Madeleine in the first season of La Femme Nikita.
Jayne Atkinson originally auditioned for the role of The President's wife, Martha Logan, in Season 5. Jean Smart was eventually cast as Mrs. Logan, and Atkinson was later cast in the role of CTU executive Karen Hayes. In a subsequent interview, Atkinson said that her audition for the role of Martha Logan had gone well, but that Jean Smart was perfect for the part. In addition, she felt a stronger connection to her role as Karen Hayes.
Six main actors from the movie _Robocop (1987)_ have been cast as main characters throughout the '24' series. They include: 'Peter Weller': plays Officer Alex J. Murphy in Robocop and Christopher Henderson in 24. Kurtwood Smith: plays Clarence Boddicker in Robocop and Senator Blaine Mayer in 24. 'Ray Wise': plays Leon Nash in Robocop and Vice President Hal Gardner in 24. Paul McCrane plays Emil Antonowsky in Robocop and Graem in 24. Jesse D. Goins plays Joe Cox in Robocop and Alan Hayes in 24. 'Edward Edwards' plays Manson in Robocop and Colonel Lamb in 24.
In preparation for Season 7 of this series, the executive producers and staff writers strongly considered moving the action of the story from Los Angeles to New York. They felt that L.A. had been the target of terrorist attacks too many times in the previous six seasons, and that the location of the drama needed an update. They debated whether to place Season 7 in New York City or Washington D.C., and ultimately decided on the District of Columbia. They reasoned that, because the majority of principal photography would still film in Los Angeles, that it would be easier to fake Washington D.C. using L.A. locations, than to try to effectively fake New York. The production made three trips to Washington D.C. before the WGA strike in November 2007, the other Washington shots were inserted in the post-production process using green screens.
Cherry Jones told Newsweek Magazine that her models for her characterization of President Allison Taylor are Eleanor Roosevelt, Golda Meir, and John Wayne. Cherry Jones also portrays Eleanor Roosevelt in Amelia (2009).
Seasons 1 and 3 are the only ones where no changes to the main cast (e.g. guest stars being upgraded to regular status) occur during the season. They are also the only two seasons in which each main cast member appears in every episode of the season.
Season 6 shares many plot elements with the video game Call of Duty 4: Modern Warfare (2007). Both plots involve a one-armed, ultra-nationalist Russian selling nuclear bombs to a Middle-Eastern faction. Both plots involve detonating a nuclear bomb with the ultra-nationalist wanting the Middle Eastern faction to take the blame. Both feature characters named Al-Assad (Al-Asad in Call of Duty).
According to Kiefer Sutherland Nina Meyers was a loyal CTU agent in the script, but the character was changed into a villain by the writers after they had already filmed episodes of "good Nina". She was also supposed to be dead when Jack shoots her on the side of the road, and again the decision was made after they had shot the scene.