It may have been broad daylight, but at the unlikely witching hour of 3 p.m., local zombies rose like clockwork from the slightly damp lawn of the Santa Barbara County Courthouse Sunken Gardens on Saturday to perform “Thriller!”

During the annual ritual called Thrill the World, nearly 100 of the local undead, led by Santa Barbara nonprofit World Dance for Humanity, join costumed creatures from all over the planet twitching, stomping and growling in unison as they bring back to life the choreography of Michael Jackson’s iconic music video “Thriller.”

Community members of all ilks and ages are invited to step onto the dance lawn, but don’t be tricked by the short four- to five-minute duration of the pre-Halloween gyrations.

“Thriller” takes some time to learn, and World Dance participants, even those like me who have been doing it for years, start regular practices at least two months ahead of showtime.

We begin with the very slow version of the song, which includes verbal instructions such as “shoulder step,” “booty bounce” and “air guitar,” and work up through the slow, medium and regular speeds with only the music to guide us.

Scary stuff.

We rehearse in the heat of the day on Saturday mornings across from Chase Palm Park; Wednesdays in the dark of night on the outdoor stage at Oak Park; and sometimes at home alone following along with online dance videos.

We go all out with costumes that we’ve pulled together from thrift store finds or vintage stuff that’s been hiding in the tops of our own closets.

This year, I wore a velvety pink hat from the 1940s that had belonged to my mother. A fan of spooky movies, my Mom would have loved that her sweet half-hat was being used for a “Thriller” costume.

The most important part of “Thriller,” though, is not the clothes, or how well you know the dance (after all, zombies are not that great on their feet).

It’s about having fun and being yourself — or maybe someone else.

As we like to say in World Dance: “Just have fun because nobody cares.”