It follows Bill, a stick figure who struggles with memory loss and surreal visions, among other symptoms of an unknown neurological problem.

It mostly consists of stick figures with stylized real-life footage appearing in many split-screen windows that are photographed through multiple exposures.

It's Such a Beautiful Day received widespread critical acclaim, with its experimental storytelling and surreal elements being singled out for praise.

[4][5][6] Bill is a man whose daily routines, perceptions, and dreams are illustrated through multiple split-screen windows that are in turn narrated.

He is then taken to a hospital but his health fluctuates rapidly and confuses his doctor, who concludes that Bill will not die, which surprises and inconveniences his relatives.

The narrator details the surreal history of Bill's family, many of whom suffered from mental illness and died in unpleasant ways.

A few days after leaving the hospital, Bill receives a call telling him that his mother had died in a "fit of senile hysterics".

He starts to repeat and then forget various tasks, such as buying food and going for walks, and he does not seem to understand that he is ill. His doctor eventually explains that he does not have long to live.

[7] The film was extremely well received by critics, describing it as "essential viewing" and "simply one of the finest shorts produced over the past few years, be it animated or not".

The DVD featured an extensive "archive" of over 100 pages of deleted scenes, Hertzfeldt's production notes, sketches, and layouts, as well as a hidden Easter egg that plays an alternate, narration-free version of the film to highlight the sound design.

It continued the dark and philosophical humor of the first film, seeing Bill's recovery haunted by the apparently genetic inevitability of his mental illness, the lack of control over his own fate, and the sudden death of a loved one.

[17] The final chapter of the trilogy, It's Such a Beautiful Day, was released in 2011, winning several awards, including a Special Jury Prize from the Hiroshima Animation Festival.

In 2024, It's Such a Beautiful Day was re-released to theaters for the first time since 2012, paired with the release of Hertzfeldt's newest animated short film ME.

Critic Tom Huddleston described it as "one of the great outsider artworks of the modern era, at once sympathetic and shocking, beautiful and horrifying, angry and hilarious, uplifting and almost unbearably sad".

[5] Steven Pate of The Chicagoist wrote of the film, "There is a moment in each installment of Don Hertzfeldt's masterful trilogy of animated shorts where you feel something in your chest.

It's an unmistakably cardiac event that great art can elicit when something profound and undeniably true is conveyed about the human condition.

"[32] Mike McCahill of The Guardian called it "funny, oddly affecting and cherishably personal" and said that "in a better world, this would be on 300 screens, and filler such as The Croods would have to be smuggled in under the radar".

[33] Paul Bradshaw of Total Film called it "an existential flip book and a heartbreaking black joke: stickmen have never looked so alive".

[34] Glenn Heath Jr. of Little White Lies gave it a 5/5 score and called it "one of the great films about memory, perspective, and past history".