The plot revolves around Taylor Diehl, a young boy who discovers that a newly inherited grandfather clock can be used to turn back time 12 hours, which he does repeatedly in the hopes of preventing his parents' impending separation.

Through an inscription he reads on the newly arrived family heirloom—his grandfather's old clock—he discovers it holds the extraordinary ability to turn back time by 12 hours, so he sees a glimmer of hope.

He also manages to expose him to nuts on their lunch date, so it ends soon after Jen stabs him with his EpiPen Each attempt to alter the present not only leads to frustrating failures but also brings unforeseen consequences.

Together, the siblings hatch increasingly elaborate schemes to harness the clock's power, resorting to creative yet risky solutions in their desperate bid to save their parents’ marriage.

As the clock ticks down, the siblings must reconcile their desires with the inevitable reality of life, ultimately discovering that sometimes the most valuable moments are found not in changing the past, but in embracing the present.