For 20 years, Disneyland has been home to a quirky SoCal tradition: Bats Day. 

That's the annual Goth gathering at the park, featuring a meet-up day in Disneyland and other offsite events like concerts, crafts markets and even a costume ball. This year's event takes place May 5 and 6.

The celebration isn't an official event sponsored by Disney. It's a labor of love for the organizers who have watched the Bats Day crowds grow each year.

"Bats Day has kind of become one of those staples now. We have probably about 8,000 to 10,000  people come to Disneyland for this Goth convention," said founder and executive producer Noah K.

The event started as a group of Goth friends getting together at Disneyland, but as interest grew with the help of social media, the organizers decided to add the other offsite fun to the weekend schedule.

"For the last couple years we did what we called the Bat's Day Happy Haunts Swinging Wake Costume Ball, our homage to Disneyland's Haunted Mansion. We would basically ask all the attendees to come dressed as a spirit, ghost or a character from the Haunted Mansion," Noah said.

But this year's anniversary will be bittersweet. Due to financial constraints, the organizers have decided to scale back, cancelling all those extra events and leaving just the meet-up in Disneyland.

"What's happening is we're saying goodbye to the entire weekend at this point, and we're going back to the grassroots of the event which was the park meet in itself," he said.

The annual 'Black Market' bizarre, where makers of Goth-themed fashion and gifts sell their creations, will be the greatest loss, Noah said.

"[The Market] really generated a lot of revenue for mom and pop vendors that had small businesses selling wares. For us to lose that in this community I think is a big hit," he said.

Bats Day may never again be what it once was, but on the bright side, they'll always have Disneyland.