Twilight the movie is from a series of four books
Twilight - the movie adaptation of Stephenie Meyer's teen vampire novels - is to be released early, in the slot left by the delayed Harry Potter film.
Twilight's US release was to be 12 December but is now 21 November. It is not known if the UK will follow suit.
Harry Potter and the Half-Blood Prince has been pushed back to July 2009.
Meyer is still relatively unknown in the UK but in the US her books create the kind of excitement enjoyed by those of JK Rowling.
The Twilight film from Summit Entertainment stars Kristen Stewart, recently seen in Into the Wild, and Robert Pattinson, who played Cedric Diggory in two Harry Potter films.
Rob Friedman from Summit explained the changed release date for Twilight, following the move for Harry Potter and the Half-Blood Prince.
"We saw a unique opportunity to slot in our film, which has been gaining tremendous awareness and momentum over the past several months," he told Hollywood Reporter.
"We by no means are trying to fill the shoes of the incredible Potter franchise for 2008. Rather, we are just looking to bring the fans of Stephenie Meyer's incredible book series the film series as soon possible."
Meyer backed up Mr Friedman's comments, saying on her website that neither she nor Summit had had anything to do with the change to the Harry Potter schedule.
In the US, Meyer's books are highly anticipated. Earlier this month, thousands of fans, many clad in the outfits of Meyer's characters, gathered at midnight bookshop parties.
Stephanie Meyer's books are highly anticipated in the US
The reason for this frenzy was the release of Breaking Dawn, the fourth and final part in Meyer's vampire series, The Twilight Saga.
The excitement is reminiscent of that created when a new Harry Potter used to hit the shops.
Meyer's Twilight books follow the story of Bella Swan, an ordinary high-school student who falls in love with the "vegetarian vampire" Edward Cullen.
Though Meyer is not yet a household name in the UK she certainly has a growing body of largely teenage fans, who mainly learn about her books through word of mouth.
The sixth Harry Potter instalment was also supposed to have its Royal premiere in London on 17 November.
Alan Horn, president of studio Warner Bros, said the decision to move the film to 2009 was taken to guarantee the studio a major summer blockbuster that year.
He also blamed the Hollywood writers' strike, which hit the film industry hard earlier this year.
Mr Horn said the strike, which ended in February, had "impacted the readiness of scripts for other films".
The move will mean a two-year delay between the film adaptations of books five and six in JK Rowling's fantasy series.
But it will shorten fans' wait between Half-Blood Prince and Harry Potter and the Deathly Hallows, which will be released in two instalments and are being shot simultaneously next year.
It is thought actors Daniel Radcliffe, Rupert Grint and Emma Watson will reprise their roles.
The release date for part one is tentatively set for November 2010.