At 11.11.11 on 11.11.11, the time and date will be a perfect same-numbered palindrome, reading the same backwards as forwards, an event which can only happen on one day every 100 years.

And even the most skeptic will stop for a moment to reflect on the unique occurrence, which will not come around again in the lifetime of most of us.

Among other things, 11.11.11 will be:

* Armistice Day, celebrated around the world.

* A day of spiritual significance for those who believe the number 11 has a mystical power.

* A very special day to get married or have a birthday (especially if it’s your 11th).

* Perhaps even the end of the world, according to some “prophecy” web forums.

The reason the date is so unusual is that 11.11.11 is the only double-figure palindromic date, since there is no 22nd month.

The last time it happened, on November 11 1911, an almost supernatural event saw temperatures drop by more than 60 F in a single day.

This was the Great Blue Norther, a cold snap which hit the U.S. causing blizzards and tornadoes as well as record falls in temperature.

In Kansas City, it was as warm as 76 F (24 C) in the morning – but this had dropped to 11 F (-12 C) by the end of the day.

A new film will be released on Friday, entitled simply 11-11-11, predicts that the day will see the opening of a portal in to Hell

A new film will be released on Friday, entitled simply 11-11-11, predicts that the day will see the opening of a portal in to Hell, and says: “On this day, innocent blood will spill.”

11-11-11 film by Darren Bousman, director of several entries in the Saw franchise, features a man whose family dies in a car crash at 11:11 a.m., and who then begins to be haunted by the number 11.

It plays on beliefs long held by some spiritualists, who say that the number has a special significance and claim that many people have a mystical attraction to the time 11.11.

One group believes that 11.11 is the special symbol of the “Spirit Guardians”, a group of 1,111 celestial beings who supposedly look after mortals and manifest themselves in mid-morning.

Most of those who have chosen this Friday as a day to get married are more attracted by the pleasing coincidence than by any deeper significance.

Wedding mania will be even more pronounced overseas, such as in India where thousands of couples have judged the date to be auspicious for a successful marriage.

The day will also be one of celebration for a number of children who will be turning 11 on 11.11.11.

Most famously, the 11th of November is Armistice Day in the UK – Veterans Day in the U.S. – when is celebrated the end of World War I and commemorate the victims of that war and subsequent ones.

The end of the Great War came on November 11, 1918. Given the carnage seen in the war, we can assume that the date was not deliberately chosen, but was simply the earliest possible opportunity for a ceasefire.

However, the decision to end the war at exactly 11 o’clock certainly was deliberate, at the Armistice was signed around five in the morning (Paris time), to take effect at the symbolic point a few hours later.

Tragically, fierce fighting continued right up until the official ceasefire, and one American soldier was killed at 10.58.

There is no real significance to the date 11.11.11 – not even at the time of 11.11.11 – but it is a classic example of apophenia, the human urge to see patterns in essentially random events.