They rolled out the pink carpet at Clift Hotel, brought in the Twilight Vixen Revue dancers, and crowded the Redwood Room with people who make the event happen.
"We make a difference nationally, globally. San Francisco is kind of like what we call the gay Mecca. There's so much to celebrate that's why we honor the people who make a difference in our community," said party creator Mark Rhoades.
It's called "40 and Fabulous." It's a far cry from the first one in 1970, called "A Gay-In." A few thousand people showed up at that first event. This year they expect more than a million people in San Francisco.
With parades in years past, its roots came from the Stonewall raid in New York. It started small, simply.
"We were babies then. We had no idea of how difficult and challenging it would be," said philanthropist James Hormel.
But change has come.
"It's diverse and that's one of the things. That's the hallmark of the spirit of this evening," said Andrea Shorter from Equality California.
"And is a major change on a very, very positive level," said clothing store owner Wilkes Bashford.
Corporations recognize that. PG&E is a major sponsor.
"They think about their employees and they think about the community and they try to match both together," says Don Howerton from PG&E.
It was also a chance to recognize the contributions of the LBGT community.
"God has endowed these very special people with creative talents that have made such a massive difference in the arts," said socialite-philanthropist Joy Bianchi.
Shannon Wentworth's travel agency plans lesbian vacations where women interact with a country, perhaps cleaning beaches or creating children's libraries.
"If gay people keep doing gay things, we're not really going to get anywhere. But if gay people reach out and show our hearts, we're going to make a lot of progress in human rights," said Wentworth.
What they will celebrate this weekend.