Angered by the passage of a law banning same-sex marriage, gay rights activists are urging people to call in "gay" across the United States and skip work on Wednesday.
They also want people to buy nothing, to show off the economic muscle of the gay community, and spend the day doing volunteer work instead.
"Day Without a Gay," modelled after the 2006 immigrants rights protests that swept from California to Texas, is intended to show how important gays and lesbians are to the US economy.
The move is a reaction to California voters' passage of Proposition 8 that bans gay marriage - which had been legal in the state since June.
Similar propositions also passed November 4 in Florida, Arizona and Arkansas, states where gay marriage was not legal.
"A day without gays would be tragic because it would be a day without love," reads the home page on www.daywithoutagay.org.
"On December 10, 2008, the gay community will take a historic stance against hatred by donating love to a variety of different causes.
"On December 10, you are encouraged not to call in sick to work. You are encouraged to call in 'gay' - and donate your time to service!"
The website includes suggestions for people who fear skipping the day at work, such as writing to politicians or discussing the issue with friends.
The protest is timed to coincide with International Human Rights Day on Wednesday.
Another website, www.jointheimpact.com, claims that gays and lesbians contribute 700 billion dollars a year to the US economy - the same amount as the government bailout - and asks people not to buy anything Wednesday to show the economic strength of gays and their supporters.
The day will culminate with an evening march and rally in San Francisco.