Take the opening of the sparkling new Contemporary Jewish Museum, combine it with one of the Jewish calendar’s “best kept secrets,” add in a wide variety of cultural arts offerings and what do you get? A recipe for one of San Francisco’s most unique events of the year, DAWN 2008.

Thousands of revelers descended on the CJM on June 7 for the DAWN ’08 cultural arts festival, which celebrated both the museum’s long-awaited grand opening and — one night early — the holiday of Shavuot.

Co-presented by the Museum and Reboot, a nonprofit dedicated to helping the younger generation of Jews explore and redefine Jewish identity and community, DAWN ’08 presented an array of Jewish-oriented entertainment designed to appeal to a young adult community. The concept of an all-night Shavuot party was first conceived by Reboot in 2004 as a way to transform the holiday’s traditional red-eyed Torah study sessions into a more appealing celebration.

Festive vibes abounded early in the event, which began at 8 p.m., as the museum lobby overflowed with nattily dressed patrons of a wide range of ages. Guests had to enjoy their libations in the lobby because drinks weren’t allowed into any exhibit areas.

“It was an amazing fashion show, in terms of the attendees, and it was fun to people-watch,” said documentary filmmaker Sam Ball, whose short film “Lalo’s Jerusalem” was part of the DAWN Film Series. Ball says the film, about a Salvadoran American teen who discovers his great-grandmother was a Jew who fled to El Salvador from Nazi Germany, received a terrific response.

The main stage conversation with “Everything Is Illuminated” author Jonathan Safran Foer was packed to capacity, with people being turned away at the room’s door. But Safran Foer was hardly the only attraction. At the same time, Moshe Kasher was delivering a raunchy set of standup comedy in the second floor’s “Yud” gallery, while Rabbi Jonathan Jaffe of Congregation Emanu-El in San Francisco led a discussion in the board room about “rabbinic tales of deceit at Mount Sinai” and how to apply the lessons of those to the modern world.

Other rabbinical scholars fielded questions at the Stump the Rabbi booth, while free bagels from Miller’s East Coast West deli proved extremely popular with the younger patrons who seemed to have missed dinner before arriving.

Guests turned away from Safran Foer’s talk soon formed a line to enter the same space to see musical headliners Dengue Fever, which rocked the crowd with a unique “Cambodian pop rock psychedelic” sound.

Charismatic lead singer Chhom Nimol dazzled with her groovy dance moves and melodic Cambodian vocals, while Jewish guitarist-vocalist Zac Holtzman sported an old-school rabbinical beard as he led the band through a set of mostly up-tempo grooves.

“I was overwhelmed by the attendance and excitement generated by the opening and program,” said DAWN co-organizer Anne Cook. “It was like the best kind of smorgasbord — the eclectic programming matched the eclectic crowd as they ran from one place to another trying to take it all in.”

Dengue Fever’s set was followed by a midnight Shavuot ritual dubbed “I-Vow-Now.” Amichai Lau-Lavie of New York’s Storahtelling, DAWN co-founder Amy Tobin and an offbeat character in a blue rabbit costume named Scotty the Blue Bunny led the audience through a multimedia ritual vow between the divine and the human. It combined reverence for the sacred revelation of Shavuot with some ribald satire from Scotty that matched the late-night party vibe.

As the 1 a.m. hour approached, acclaimed musician Yossi Fine spun trance grooves in the lobby while some local indie rockers prepared to deliver a live score to a screening of the classic 1926 silent film “Benya Krik.”

“It was way beyond our expectations of attendance, and we were thrilled to be able to offer such a diverse and eclectic array of entertainment and programming,” said Stacey Silver, the museum’s director of marketing and communications.

Silver said more than 3,500 people attended; at times people were turned away because the space was at capacity. By midnight, though, the crowd had thinned enough to start letting in more people.

“Obviously this event shows the need for both the CJM to exist, and the need for events that are culturally and traditionally significant to young adult Jews,” DAWN co-organizer David Katznelson said. “This event gave a platform for all these Jewish artists to interpret and showcase their art in an amazing way.”

The party at the museum went strong until 3 a.m., then headed over to the Mariposa Hunter’s Point Yacht Club for discussions, music, the sunrise and, perhaps most importantly, breakfast — an appropriate ending for an all-night shindig.

Museum opens with huge party