(Associated Press) — It may not have started long ago or in a distant galaxy, but every May 4, it’s as if images, memes, and special promotions themed around “Star Wars” exert an irresistible pull.

May 4 — or May the 4th, as followers often say — has transformed over the years into Star Wars Day, an unofficial holiday dedicated to the legendary space saga and its entire franchise.

What is Star Wars Day?

Star Wars Day was devised by fans as a clever homage to one of the series’ most iconic lines, “May the force be with you.” Understand now? Well, May the 4th be with you as well.

It’s not an official holiday but has become so well-known that even former President Joe Biden marked it last year when “Star Wars” actor Mark Hamill dropped by the White House a day beforehand.

“I think it’s a very clever way for fans to celebrate their passion and love for ‘Star Wars’ once a year,” said Steve Sansweet, founder and executive chairman of Rancho Obi-Wan, a nonprofit museum in California that has the world’s largest collection of “Star Wars” memorabilia.

How did it begin?

The phrase “May the 4th be with you” was used by fans in the years after the first film was released in 1977, and even appeared in a British political ad in 1979 celebrating Margaret Thatcher’s victory as prime minister on May 4 that year.

For some fans, the official Star Wars Day comes on May 25, the date of the first film’s release. The Los Angeles City Council even declared the date to be Star Wars Day in 2007, although the California Legislature voted in 2019 to designate May 4 as Star Wars Day.

How has it spread?

May the 4th caught on informally among fans through inside jokes shared on social media and viewings of the films to mark the occasion. Businesses eventually joined in on the fun, with brands ranging from Nissan to Jameson Whiskey running ads or posting on social media about it.

Disney, which acquired Lucasfilm in 2012, embraced the day as a way to further promote the franchise with merchandise, special screenings and other events surrounding the brand.

Not all “Star Wars” fans are enthused about how ubiquitous the once-underground joke has become. Chris Taylor, a senior editor at Mashable and author of “How Star Wars Conquered the Universe,” labels himself a “May the 4th grinch” in part because of its commercialization.

“I love a good dad joke as much as anyone, but my God you can take it too far,” Taylor said.

How is it being celebrated this year?

The day is being celebrated on a large and small scale this year. Disney+ is launching the new series “Star Wars: Tales of the Underworld” on the date, and it comes as the second season gets underway for another franchise series, “Andor.”

It also follows the announcement that a new stand-alone “Star Wars” film installment starring Ryan Gosling will be released in 2027.

Disney marks the day with the launch of new “Star Wars” merchandise, ranging from lightsaber sets to jewelry.

Most Major League Baseball teams have marked the day in recent years with special events incorporating “Star Wars” characters. For example, the San Francisco Giants sold special tickets for Saturday’s game that included a bobblehead portraying pitcher Logan Webb as “Obi-Webb Kenobi.”

It’s hard to find a place where May the 4th celebrations aren’t occurring, from bakeries serving cookies with a “Star Wars” theme to concerts featuring the memorable scores of the films.

It’s a town-wide celebration in New Hope, Pennsylvania, which shares its name with the subtitle of the first “Star Wars” film. The town of about 2,600 people, located 30 miles (50 kilometers) northeast of Philadelphia, plans to have costumed characters throughout town with restaurants serving themed items like a “YodaRita.”

“I would always joke around and wish people ‘May the 4th’ — but taking it to this level, I’ve definitely upped my ‘Star Wars’ nerdiness,” said Michael Sklar, president of the Greater New Hope Chamber of Commerce.