Last year, more than 90 bookstores across the state participated in the inaugural California Bookstore Day, throwing special events and carrying items created specifically for the occasion. This year, the event has grown into Independent Bookstore Day, with some 400 stores celebrating across the country.

The idea was born when Green Apple Books and Records’ Pete Mulvihill, who also serves on the board of the Northern California Independent Booksellers Association, noticed a spike in sales on Record Store Day and wondered why there wasn’t a similar day for bookstores. The NCIBA sponsored the event and writer-editor Samantha Schoech (also Mulvihill’s wife) took on the producing role, even starting CBD Publishing to make some of the items.

The hope was always that the event would reach a national scale.

“We weren’t sure when we wanted to go national — if the American Booksellers Association was going to take it on — but we felt like we’ve done this and we know what we’re doing and we’d love a chance to improve on the kinks from last year,” Schoech said by phone. “So we invited the nine regional executive directors (of the nine regional trade associations) to see if they wanted to do it, and to figure out how we could still produce it but make it happen all over the country.”

She added that it was ultimately the stores’ widespread demand that convinced the regionals to get on board.

Last year’s participating stores reported a collective increase of about $150,000 in the day’s sales, as NCIBA executive director Hut Landon told Chronicle book editor John McMurtrie ealier this month. “Indies are doing well,” Landon said. “Sales have been up nationally and locally each of the past three years.”

Other big publishers are helping by creating special Bookstore Day items, like a signed, limited edition chapbook by Roxane Gay and a handwritten broadside from Stephen King’s Finders Keepers.

“The publishers participating in Bookstore Day at all by producing these special items for us is sort of amazing because they’re not making big profits,” she said. “They’re doing it only because they like the idea and they love independent bookstores and they know what independent bookstores do for their books and their writers.”

Local events range from a Mad Tea Party at The Booksmith to in-person advice on your online dating profile, courtesy of Dave Eggers at Books Inc. Castro, and include daylong festivities at many locations.

For more information, go to cabookstoreday.com.

This article originally appeared in The San Francisco Chronicle.