The signature tequila cocktail is called a Hot Flash. The playlist skews towards nostalgic hits from the 80s, 90s and early 2000s. Cis men are politely asked to just stay away.

Founded in Chicago by two friends in their 40s, the Earlybirds Club is a party designed for women and trans and non-binary people who have jobs and responsibilities that start early in the morning – but who still want a chance to dance crazily with their friends.

The dancing starts at 6pm and ends around 10. Just a year after Laura Baginski and Susie Lee threw their first early-evening party in Chicago, the event has already started touring the country, from Brooklyn to Los Angeles. And the founders, whose clever idea has become a full-time business, keep getting more requests, from as far away as Dubai, Mumbai and Vancouver, as well as across the US, Baginski said. Earlybirds Club’s first anniversary party this weekend quickly sold out a Chicago venue that holds 1,000 people, she said.

“Everyone is smiling and screaming lyrics at the top of their lungs. It’s an experience that, especially in these times, feels so necessary and therapeutic,” Baginski said.

By their 40s and 50s, many women are caretakers for others. “It’s important for us to remember to create joy for ourselves – because in this age group, we don’t do that,” Lee said.

The two women, both 49, have known each other since high school, when they both worked on the school paper and were, in their words, “dorks”, though Lee also identified as a “goth new wave kid”. Neither has a background in party promotion: Lee was a makeup artist for 20 years, while Baginski was a journalist and then worked in marketing for non-profits.

Both founders are definitively gen X; their DJ is a millennial, “so she understands what millennials want”, Baginski said. But their party has attracted a much wider range of generations than they expected.

“We’ve had people bring their daughters,” Baginski said. “We’ve also had women in their 60s, sometimes in their early 70s, coming, which is so cool. I think younger women love to see that – I know I do.”

They also did not expect just how enthusiastic partygoers would be about a chance to dress up, the founders said – devoting time to finding vintage outfits and doing their hair in decades-old styles. “We did a 90s prom where people bought prom dresses in a 90s style to wear,” Baginski said. “One woman wore the same dress that she wore to her 1989 prom, which is like, kudos, you win.”

While the primary goal of the party is offering a fun night out that focuses on friends, not flirtation, the dancefloor experience often ends up being cathartic, the founders said. Lee is a cancer survivor still dealing with health challenges, and when the founders share her story at events, they often hear from participants who are also cancer survivors or in treatment.

The Earlybirds Club’s first foray into Los Angeles in January ended up being disrupted by wildfires, but some partygoers showed up for the pair of parties anyway. “Was not feeling up for a dance party last night … but it turned out to be therapeutic and maybe exactly what people needed,” one woman at posted on Instagram after the event. “I saw ladies crying while dancing and it just made sense.”