People around the globe will experience a numerically auspicious hour and date this Friday at 49 minutes before noon; 11:11 on 11/11/11.
While millions may marvel at the once-per-century string of ones on their clocks, mobile devices and calendars, to be sure much of humanity will hardly bat an eye.
But many numerologists, metaphysicists, psychics and their followers, occultists and conspiracy theorists will be watching for signs of some broad humanistic awakening, a harmonic convergence, even a portal opening into a new dimension, as some experts predict a major "shift in consciousness."
Thousands will gather for 11/11/11 ceremonies, trance dances or day-in-the-life video projects around the world, and several Facebook pages marking the date have popped up.
A Spanish charity for the blind named ONCE (Eleven) is holding a special lottery with 11 one-million-euro prizes and a super jackpot worth 11 million euros.
From Israeli-born psychic Uri Geller to "visionary" author and 11-11 expert Solara -- and even fans of the movie "This Is Spinal Tap," for whom the number 11 holds cherished meaning -- many are hailing the synchronicity of the date.
"It's certainly significant to have a triple master number" on the calendar, Solara, who goes by one name, told AFP.
"I envision a big shift in consciousness on the planet, and it's coming to a point with this date."
Solara lives in Peru, and while she is keeping her 11/11 plans secret, she says groups in more than 50 countries will mark the auspicious moment.
At 1111 GMT they will "join together and sit as silent watchers who oversee worlds within worlds," and whose perspective will "strengthen the resonance of trueness just by their presence," she said.
For numerologists, Freemasons and occult groups, 11 holds special resonance.
Some say it has psychic properties or represents a channel to the subconscious, while others stress its inborn duality, a reflection of the good-and-evil paradigm that Solara believes has been present since the dawn of humanity.
The Internet is humming with bloggers who insist the mystical 11 pops up with alarming regularity in schemes such as 9/11. Not only did the terror attacks occur on September 11, they note, but the twin towers resembled an 11, and the first plane to strike the World Trade Center was Flight 11.
Others cite the prophecy of Saint Malachy, who in the 11th century predicted there would be 112 popes before a biblical apocalypse. The current pontiff, Benedict XVI, is the 111th pope.
Historically the date carries weight. The World War I armistice was signed on the 11th hour of the 11th day of the 11th month of 1918.
"There's an interesting synchronicity in how many things in this reality align with the number 11," said Ellie Crystal, an author, psychic, blogger and metaphysical explorer.
There was an 11/11/11 100 years ago, of course, "but human consciousness was not in the same place it is today," she told AFP.
Americans and others began focusing on 11:11 over the last several decades, with the advent of the digital clock.
"They'd see 11:11 and say 'hmm,' then they'd go about their business," Crystal said. "And the next day they'd see it again. It makes people wonder, what is this whole thing about?"
It's about pseudo-scientific bunk, an example of "confirmation bias" in which people spot hits but conveniently forget misses, insisted John Hoopes, a University of Kansas professor who specializes in knocking down such theories and uses dates like 11/11/11 to teach critical thinking.
Some people use numerology "to try and understand the world, but it has about as much scientific significance as the lyrics to 'The Age of Aquarius,'" Hoopes said.
Yet Crystal and others see 11:11 as a pre-encoded trigger, an "awakening code" that could elevate consciousness.
She said some are even convinced a physical portal will open on Friday, transporting believers across a bridge from the duality of this world into a new oneness.
"A portal will not open," Crystal asserted bluntly. And, barring a horror film named "11-11-11" coming out on November 10, there will be "no doomsday, nothing apocalyptic."
That could occur 13 months later, she quipped, citing a myth that the world will end along with the Mayan calendar on December 21, 2012.
But with a Christian radio broadcaster mistakenly predicting that the rapture would occur May 21, 2001, then on October 21, some are seeing a chance to inject humor into what will in all likelihood be just another day.
The Nigel Tufnel Day Appreciation Society has been petitioning to have November 11, 2011 christened Nigel Tufnel Day, to honor the guitarist in the classic "Spinal Tap" mockumentary who shows how his amplifiers "go to 11."
So just what will happen on Friday? Those whose brains are wired for 11:11 will notice a realignment, Crystal said.
"If you don't feel it, no biggie."