Approximately 24 hours, from morning to morning, in the life of New York City-based jazz singer Vivienne Carala (Sarah Jessica Parker) is presented. On this day, she has a rehearsal in preparation for a weekend gig starting tomorrow celebrating her 25th anniversary of performing at Birdland - the rehearsal where she knows she will see Jordan (Taylor Kinney), her drummer with whom she has a casual sexual relationship - followed by an interview largely to promote her latest album. Beyond these two items, she will try to fill her day without going home knowing that her overbearing French mother, Jeanne (Jacqueline Bisset), has made another of her unexpected visits. This day is upended in its front side by a medical appointment she has told no one about, let alone her exasperated manager Ben (Common) in she being late for the rehearsal because of it, at which she receives the news of a terminal brain tumor diagnosis - the head pain symptoms which she had long ignored in being too busy to deal with it - with the best case scenario being a 14-month survival, only with treatment. Beyond the commitments of the rehearsal and the interview which are affected by the news, Vivienne, who wants to keep the news to herself for the time being in wanting to live her life, knows she has two logistical issues--needing to tell her ex-husband Nick (Simon Baker), who has custody of their teen daughter Lucie (Gus Birney), they who will have to figure out how to break the news to Lucie; and needing to have one person accompany her to the hospital the following morning, whether that person be Nick or she needing to confide to one other person. Aside from how she will process this news in relation to the people close to her including Nick, Lucie, Jeanne, Ben and Jordan, her own process of dealing with the news internally is affected by, among other things, encounters with two unexpected people, Tessa (Renée Zellweger), an old friend she hasn't seen in a while and who is out celebrating her birthday, and a Lyft driver (Waleed Zuaiter) who also seems to be having a bad day.