A complete misunderstanding of an ancient Mayan calendar has many people convinced the world will end on December 21, 2012.

Their belief is based on a supposedly ancient prediction that the planets will align on Friday, bringing about the end of the world.

Nothing of the sort will happen, of course.

Concordia professor Lorenzo DiTommaso specializes in apocalypse lore, and he says the Mayan calendar marked the beginning of a new era, not the end.

"You have predictions it seems every year, so you have this joking aspect that comes along with it and so some people believe the end of the world is going to come and other people turn it into a party," said DiTommasso.

The Mayan civilization used several calendars, and even though Friday is the end of the 7,785 year-long long-count calendar, it's akin to rolling over an odometer or the end of a century; Saturday will unveil as it should, and the long-count calendar starts fresh at Day 1.

However once the hoax of Mayan calendar destruction spread online, wiping it out with the truth has become virtually impossible.

The most bizarre aspect, for many, is crumbled hieroglyphs saying 'it will happen' -- whatever 'it' is -- on Friday Dec. 21, 2012. The ruins with this message were found in Mexico in the 1960s, but the symbols described 'it' were damaged and unreadable.

Many have used that mystery and given their imagination free rein, coming up with possible ways the world will end. One option is the appearance of an anti-Earth called Nibiru which will smash into our planet, while others prefer the notion that a planetary alignment will somehow pull the Earth apart.

The closest thing to a planetary alignment last happened 2,500 years ago, and will happen again in a few more centuries, but even if the planets were lined up on one side of the sun like a spoke on a celestial bicycle wheel, it wouldn't matter.

"Planets when they align have no influence or effect on the Earth," said Louie Bernstein of the Montreal Planetarium.

So prepare for the holidays and finish your Christmas shopping, but don't worry about the end of the world.

The only apocalypse is likely to be arriving after the holidays when credit card bills come due.