The trick to good romantic comedy is never to let the romance overshadow the comedy. Exhibit A: One Fine Day.

This featherweight confection follows two single parents who meet one ugly morning and hate one another's guts until they fall in love. Throughout the day, complications spring up like trip wires to keep them off balance -- and to keep the comic momentum bubbling along as their mutual resistance crumbles.

George Clooney plays Jack Taylor, a free-wheeling newspaper columnist whose adorable daughter Maggie (Mae Whitman) arrives at his doorstep on the first day of his ex-wife's honeymoon.

Michelle Pfeiffer plays Melanie Parker, a buttoned-down super-mom whose adorable son Sammy (Alex D. Linz) is Maggie's classmate. The kids miss an all-day field trip because of Jack's inattention to schedules, setting off a zany juggling act as the two parents -- each of whom faces a professional crisis -- trade child-care service while scrambling to keep their jobs.

The career subplots are predictably preposterous. Jack writes columns based on unverified tips, and Melanie's entire future as an architect depends on sharing cocktails with a client after work. But the desperate daylong race to get frazzled kids picked up and handed off and home safe will strike a chord with any employed parent.

Mr. Clooney and Ms. Pfeiffer generate nice chemistry as a pair of romance-averse characters thrown off balance by the attraction that manages to assert itself between cell-phone calls and bathroom emergencies.

Notable supporting characters include Robert Klein as a therapist trying to unravel Jack's coded diatribe about ''fish'' and ''cookies'' as Maggie listens in, and Holland Taylor as Melanie's matchmaking mother.

One Fine Day is not quite the Hepburn-and-Tracy dazzler it would like to be, but it is a success -- an entertaining slice of frothy fun.