Sharon Osbourne, and daughter Kelly, will open their Hidden Hills home Saturday to host a Harvey Milk Day celebration and fundraiser sponsored by the state's largest gay rights advocate, Equality California.

This year marks the inaugural May 22 Harvey Milk Day after California Govern Arnold Schwarzenegger signed into law state Senator Mark Leno's Harvey Milk Day bill in October. The governor initially rejected the measure the previous year. In vetoing the first bill, Schwarzenegger said Milk's accomplishments should be celebrated at the local level.

But Milk's profile soared during the intervening months, leaving the Republican governor with few options but to sign the legislation. President Obama honored Milk with a Medal of Freedom, the nation's highest civilian award; the California Museum, which was conceived by Schwarzenegger's wife, Maria Shriver, was about to induct him into its California Hall of Fame; and a movie about his life, Milk, drew national attention to the tumultuous early years of the gay rights movement.

Harvey Milk Day honors the gay rights leader on his May 22 birthday. Milk would have turned 80 this year.

Milk became the first openly gay elected official from a major U.S. city when he was elected to the San Francisco Board of Supervisors in 1977. He won on a platform of civil rights but his tenure was cut short when he was gunned down by a disgruntled former supervisor, Dan White, the following year.

“Harvey Milk was a champion for seniors, for working people and for those who didn't have a voice, and his courageous work set the stage for many of the key civil rights advances we enjoy today,” Geoff Kors, executive director of Equality California (EQCA), said in a statement.

The Osbourne family, which includes singer-songwriter Ozzy Osbourne, daughters Aimee and Kelly, and son Jack, attracted a huge following off the success of MTV's reality series The Osbournes.

Sharon Osbourne has gone on to host her own talk show, The Sharon Osbourne Show, and later became a judge on the talent shows The X Factor and America's Got Talent.

Saturday's sold out Harvey Milk Day event will include music by Booby Trap!