The movie was released about six months after Saturday Night Fever (1977). The picture is considered as being a studio programmer cashing in on the success of that movie as the film's title featured the other big day of the week-end (Friday rather than Saturday) in which people go out at night.
The name of the discotheque where the movie is set was The Zoo. The nightclub used for the Zoo was the no longer remaining Osko's which was situated at 333 South La Cienega Boulevard, south of 3rd Street, Los Angeles, California. The club was demolished during the 1980s and in its place was built a Loehmann's dress store. Osko's was the first name of its owner Osko Karaghossian who appeared in the film. Osko's Disco was famous for being like a labyrinth as well as having four dance floors.
The ice cavern-themed room 'The Cave' seen at the Zoo disco in this movie was an actual a real room that existed at Osko's Los Angeles nightclub. The room can also be seen in another movie from the same year, Jennifer (1978). Jennifer is also the name of Debra Winger's character in 'Thank God It's Friday'.
Actors Otis Day (billed as DeWayne Jessie) and Ray Vitte playing Floyd and Bobby Speed respectively, both had previously appeared in the disco-soundtrack film Car Wash (1976) which was arguably the first ever disco movie.
One of the young stars in the film, Terri Nunn, would go on to front the band Berlin, whose song called 'Take My Breath Away' they sung in the later movie Top Gun (1986), would win the Best Music - Original Song Academy Award (Oscar) in 1987, the statuette though going to Giorgio Moroder (for music) and Tom Whitlock (for lyrics).
The film is also known as "TGIF" / "T.G.I.F" , the well-known acronym expression for "Thank God It's Friday". This can be seen in these letters being highlighted in one of the movie's original theatrical posters.
This film has garnered a reputation from a number of sources, including from film critic and historian Leonard Maltin, as perhaps being the worst ever movie to win an Oscar (Academy Award) which it won for Best Song - sung by Donna Summer.
Show-business trade papers such as 'The Hollywood Reporter' announced that director Robert Klane did a touch-up and polish on Armyan Bernstein's screenplay as well as stating that Klane was the co-screenwriter of the movie's screenplay yet Klane received no writer's credit on the picture.
In the USA in 1978, the song "Last Dance" sung by Donna Summer, went to number three on the Billboard Hot 100 Chart, and topped the Hot Disco Action Chart, now called the Hot Dance Club Play chart, for six weeks.
The picture had three working titles: "Disco", "After Dark", and "Discotheque". It was first named "Discotheque". This was then changed to the shortened version of this word, "Disco". Then the title was changed again, this time to "After Dark". In the end, the movie was called "Thank God It's Friday".
The New York publication 'The Village Voice' reported that the picture had test screenings conducted in the USA's Midwest (aka the American Midwest aka the Midwestern United States of America). Of particular interest was any negative audience reaction to a scene where two men are seen disco dancing together. Test audience results showed that there were no significant negative responses to this scene and as such it remained in the picture.
The 25th June 1979 edition of the New York publication 'The Village Voice' reported that 'Kenny Freidman' was a producer on this picture but in the end there is no producing billing for him in the picture's credits.
In the later film The Big Chill (1983), Michael Gold (Jeff Goldblum) wants to open a night-club. In Goldblum's earlier movie, Thank God It's Friday (1978), which had been made and released around five years earlier, his Tony Di Marco character was a night-club owner. Both films were made by the Columbia Pictures studio.
The 7th September 1977 edition of show-business trade paper 'Variety' reported that actors 'Neil Thompson' and Patrick Burn would be appearing in this movie but in the end their is no billing for the two in the picture's credits.