An anonymous email says Facebook will close for maintenance from Feb. 29-31, and urges users to "Share this message with at least 15 of your friends for the best chance of alerting everyone."
According to one version of the advisory, the disruption could be catastrophic.
National Guard troops will go on alert on both the East and West Coasts, because of the potential of unrest when people find out they have time to do something else.
Also, the U.S. Chamber of Commerce forecasts a huge increase in employee productivity. One reader wrote the Bulletin to say that the National Transportation and Safety Board expects a huge drop in accident rates because people will actually be able to think about what they are doing.
It's all in fun. There will be no such date as Feb. 29 until the next Leap Year in 2016, and there never is and never will be a Feb. 30 or Feb. 31.
The hoax may have started in France, according to a website called Naked Security.
Readers are advised to think twice.
"If you're in the habit of regularly passing on chainletters and hoaxes, chances are that you could also be the kind of person to be duped by scams and malicious links, and could inadvertently share those with your online friends too," a Naked Security advisory said. "There's an important lesson here - don't believe everything you read on the internet, and think twice before passing a story onto your friends."