Donnie Darko goofs

In the talent show sequence during Sparkle Motion's routine (1:12:50), Mrs. Farmer appears backstage, standing beside a theatre lighting fixture. That particular lamp, an "ETC Source Four Par", was not introduced until 1995.

The bicycle Donnie is shown riding in the opening sequence is a Diamondback Master TG, a model that wasn't introduced until 1990, even though the film is set in 1988.

The film is set in 1988 — a year before The Little Mermaid was released — yet Samantha inexplicably owns an Ariel doll.

During the Life Line activity in Mrs Farmer's class, Cherita responds to her question card by marking an "X" on the blackboard. When Donnie is called next, the "X" Cherita put on the board is faint, as if it had been partly rubbed out.

During his initial conversation about time travel with his science teacher, the slinky on Donnie shifts position — in one camera view it sits behind the back of his shirt collar, and in another it rests around his neck when the camera cuts between front and back perspectives.

While in the car with his father, the passenger-side wing mirror is visible outside the window. In the alternating shots between Donnie and his father, the mirror noticeably shifts its angle.

During the lifeline exercise, when Ms Farmer pulls the board into the classroom, a black duster rests on the board just above the rectangular outline. As she begins handing out the lifeline exercise cards, the duster slides to the right. When Cherita comes to the board, it has returned to its original position.

When Donnie's science teacher refers to Roberta Sparrow's book, Donnie slips a Slinky round his neck. The shot cuts to him taking the book and then immediately returns to a rear view of Donnie, showing the Slinky still pulled tight around his throat — which would not be the case if he had let go of one end of it.

While Donnie and his father are talking in the car — just before they nearly run over Grandma Death — a clapperboard is reflected in the window behind his father's head.

Middlesex, Virginia, is largely flat and lacks the hills shown in the film.

Although the film is set in Middlesex, Virginia, the majority of the cars bear Californian number plates.

Elizabeth receives her offer of admission from Harvard in October, ahead of Halloween. (The gathering that she and Donnie attend is a Halloween party celebrating her offer.) However, Harvard is one of the institutions that follow standardised application and notification dates: applications must be submitted by 1 January and letters of acceptance (or rejection) are posted on 15 April. To be consistent with Harvard's system, the film would need to be set in April rather than October.

At the start of the film, a large number of people are permitted to stand directly beneath a suspended aircraft engine whilst it is being moved by a crane. In reality, the company responsible for relocating the engine would never allow that.

Though Jim Cunningham is not married, he wears a wedding ring for the duration of the film. Richard Kelly has said this detail is meant to underscore his untrustworthy, enigmatic character.

The film is set in 1988, yet licence plates, book editions, news photographs and products from 1989-1999 appear throughout. These anachronisms complement the film's exploration of time travel and altered realities. (Chapter 4 even notes that elements from the future — for example, Mayans depicted with arrowheads — act as symbols of the future being brought into the past; these anachronisms are deliberate.)

The school's name is "Middlesex," which would ordinarily be shortened to "MHS" for Middlesex High School. Just before Donnie's conversation about time travel with his teacher, we can see the top of the school entrance. A stone cross there bears the letters "IHS". However, "IHS" is a Catholic monogram derived from the Greek form of Jesus' name (Ihsous) and is commonly placed on crosses. These letters are not intended to be an abbreviation of the school's name.

When the students each write "They made me do it" on the board, Sam Bylen is followed by Donnie Darko. Cherita Chen writes between them, but her moment is omitted from the original cut. It is restored in the director's cut.

When Donnie discovers the 1911-pattern pistol in the wardrobe, the hammer is down yet the safety catch is engaged. On a 1911-style firearm the safety cannot be applied unless the hammer is cocked. Additionally, there is a screw or pin visible on the rear left of the slide that would not be present on an authentic 1911.

When Cherita was asked to read aloud the card her teacher had given her, the word 'he' appeared where 'she' should have been, and Cherita simply corrected it.