For some, it’s Judgment Day. For others, it’s party time.

A loosely organized Christian movement has spread the word around the globe that Jesus Christ will return to earth on Saturday to gather the faithful into heaven. While the Christian mainstream isn’t buying it, many other skeptics are milking it.

A Facebook page titled “Post rapture looting” offers this invitation: “When everyone is gone and god’s not looking, we need to pick up some sweet stereo equipment and maybe some new furniture for the mansion we’re going to squat in.” By Wednesday afternoon, more than 175,000 people indicated they would be “attending” the “public event.”

The prediction is also being mocked in the comic strip “Doonesbury” and has inspired “Rapture parties” to celebrate what hosts expect will be the failure of the world to come to an end.

In the Army town of Fayetteville, N.C., the local chapter of the American Humanist Association has turned the event into a two-day extravaganza, with a Saturday night party followed by a day-after concert.

“It’s not meant to be insulting, but come on,” said organizer Geri Weaver. “Christians are openly scoffing at this.”

The prediction originates with Harold Camping, an 89-year-old retired civil engineer from Oakland, Calif., who founded Family Radio Worldwide, an independent ministry that has broadcast his prediction around the world.

The Rapture — the belief that Christ will bring the faithful into paradise prior to a period of tribulation on earth that precedes the end of time — is a relatively new notion compared with Christianity itself, and most Christians don’t believe in it. And even believers rarely attempt to set a date for the event.

Camping’s prophecy comes from numerological calculations based on his reading of the Bible, and he says global events like the 1948 founding of Israel confirm his math. But even some Christians who believe the Rapture will occur think he’s wrong.

The Rev. Tim LaHaye, co-author of the “Left Behind” series of Christian prophecy novels, said Camping “trivializes the very serious study of Bible prophecy by ignoring Jesus’ statement that everyone seems to know except him, and that is that no man knows the day nor the hour” that Jesus will return.

Camping has been derided for an earlier apocalyptic prediction in 1994, but his followers say that merely referred to the end of “the church age,” a time when human beings in Christian churches could be saved. Now, they say, only those outside what they regard as irredeemably corrupt churches can expect to ascend to heaven.

Camping is not hedging this time: “Beyond the shadow of a doubt, May 21 will be the date of the Rapture and the day of judgment,” he said in January.