Eliza Welsh, played by Uma Thurman, is a dedicated housewife preparing to celebrate her daughter Clara's sixth birthday. Unfortunately, her husband, Anthony Edwards, is frequently absent due to work commitments, leaving Eliza to juggle her household responsibilities alone with their two children, Clara (Daisy Tahan) and Lucas (David and Matthew Schallipp).
The day starts with Eliza capturing a tender moment as she takes a snapshot of Clara still asleep. However, as the day unfolds, it quickly spirals into chaos. After waking Clara, they realize they've forgotten her schoolbag at home, which frays Eliza's already stressed nerves. Adding to her anxiety, her posh French neighbor (Samantha Bee) sees her in a state of disarray, still in her pajamas.
In a flurry to rectify the situation, Eliza races to dress up and gets Clara her schoolbag back at school. But the challenges continue when she takes Lucas and their dog out, only to be confronted by a disgruntled pedestrian (Vincent James Russo) for not picking up after the dog. Upon returning home, Eliza faces another hurdle in finding a parking spot, and a rude punk proves to be a minor agent of her fate, as she pays him to vacate a nearby spot just as a parking officer approaches.
Eliza's day descends further into chaos as she takes Lucas to the park to meet her best friend, Sheila, who agrees to help by picking Clara up from school. Feeling overwhelmed, they decide to go shopping, at which point Sheila opens up about her past personal experiences. Just as Eliza seems to get a moment of respite, her car gets towed due to a film crew on her street, making it impossible for her to transport party supplies for Clara’s celebration.
The situation worsens when there’s a blunder at the bakery leading to a misspelling of Clara's name on the birthday cake. An argument ensues with the bakery attendant (Jenny Kirlin) while an impatient customer (Carol Commissiong) adds to Eliza's frustrations by critiquing her daughter's name. Balancing heavy loads, she passionately ascends the stairs of her lift-less building.
While struggling with her burdens, she encounters a messenger named Makish (Arjun Gupta), who is waiting for Eliza's husband. Moved by her plight, he offers to help her carry her party supplies and they share a moment, revealing her own lost ambitions. Tension arises when Sheila learns that Eliza has publicly shared private conversations on her blog, potentially damaging their friendship even further. Despite this, Sheila still offers her support by picking Clara up.
Amid the party preparations, Eliza is also trying to write an article themed around motherhood for a magazine contest, hoping to revive her career. When the pressures become too much, she impulsively leaves for New Jersey, ignoring her husband's calls. When she does finally answer, she guides him through a parenting crisis involving Lucas and a toy car.
As the party finally gets underway, Eliza’s husband proves to be understanding and supportive, and reconciliation occurs with Sheila. An older neighbor reminisces about her youthful delights, prompting Eliza to find herself momentarily lost in the joy of the birthday celebration.
In a heartwarming twist, later that night, Eliza and her husband retreat to the rooftop where he surprises her with a $24,000 check, money obtained from selling a cherished autographed book. It signifies a new chapter for Eliza, allowing for Lucas’s education and paving the way for her return to writing. Amid the mounting excitement, it’s clear that love is still alive in their marriage as they prepare to enjoy a newfound closeness.
