For 311 fans, the biggest holiday of the year is 311 Day, a time to celebrate the music of the reggae-rock band behind ’90s-era hits like “Down,” “Come Original” and “Don’t Stay Home,” held on March 11 (or 3/11, of course). After fans first established 311 Day on their own, in 2000 the band made it official with a concert in New Orleans, and since then the event has grown into a multiday gathering for the 311 faithful.

This year’s 311 Day takes place over three nights at the Park Theater, marking the celebration’s fourth time in Las Vegas. “You go there to have fun and enjoy yourself and immerse yourself in a different world,” 311 bassist Aaron “P-Nut” Wills says of the appeal of Vegas, and this year fans from all 50 states will converge in town for a marathon of shows. With such a loyal following and a propensity for spontaneous musical exploration, would 311 ever consider a more extended Vegas residency, maybe making 311 Day into 311 Month or even 311 Year? “Yeah, who knows? Certainly in the future I can see that happening,” Willis says. “It sounds like a good fit.”

Park Theater at Park MGM, 8:30 p.m. March 11-13, 3-day ticket starting at $183 plus tax and fee. 800.745.3000 Ticketmaster