Today is Feb. 29 – that’s a phrase you don’t  hear too often. In fact, you only hear it every four years or so.

If you’re reading this, then you’ve made it to leap day 2016 – the day we try to match the passage of time to the calendars hanging on our walls – or since it is 2016, the calendars flashing on our computers.

So, why do we have this extra day every four years? In case you are not up to speed on, well, the speed of the Earth around the sun, here’s a quick look at how/why we have a leap year.

What is a leap year anyway?

We have leap years, basically, to clean up some messy math and stroke the ego of  Pope Gregory XIII. Gregory decided he was tired of following a calendar devised by Julius Caesar, so, in 1582 he declared that a year – or one orbit of the Earth around the Sun – took 365 days. The solar system, on the other hand, said it takes the Earth 365.2422 days to make the trip. So what to do with those extra seconds? In order to keep our method of time in check with the universe, it was decided to add the minutes into day that comes around only every four years.

Thanks, Gregory.

Is there a leap day every 4 years? Not so much.

Ok, this takes math, so if you are a right-brain, you may want to skip down a few categories, we talk about marriage proposals there. We think of leap years as occurring every four years mainly because most of us weren't around the last time it didn't happen.  In something akin to Canadian rules in football, a leap year happens every year that is divisible by four, (and here's the tricky part) except for the years that are both divisible evenly by 100 and not divisible evenly by 400.

I’ll give you a minute.

The year 2000 was a leap year, but 1800, 1900 were not.

The reason for this extra bit of arithmetic is that a day added every four years is too much of a correction for the bit of extra time it takes for the Earth to make an orbit.

Why February?

The short answer – the other months already had a 29th day. But not at first. According to history.com, February originally had 30 days. August had  29 days. But when Caesar Augustus became emperor, he was miffed at the fact July, named after his uncle, Julius Caesar, had 31 days. So, he invaded February and took two days to add to his month of August – August has 31, February 28 and the leap day fits nicely into the vacant slot.

What if you are born on this day?

The chance of being born on Feb. 29 is 1 in 1,461. The chance of you being called a "leapling" or a "leaper" is close to 100 percent in some circles. Some born on  the 29th choose to celebrate their birthday on Feb. 28, others March 1. Either way, you're a Pieces and are "the dreamers of the zodiac.

"Caring and sympathetic, you typically enjoy helping others and dislike confrontation."  On the other hand, you have a hard time saying "no," and are emotional and moody. You know who you are.

What’s this about the girl asking the guy?

Ladies, get out a pen and paper and get this down – today, on the day that happens once every four years (with one exception; see above) – you can ask a man to marry you. Crazy talk, I know.  But tradition holds that on Feb. 29, the woman can do the askin’ when it comes to popping the question.

Some say we have a nun to thank, others say it was an 8-year-old girl.

According to Irish legend, a nun named  St. Brigid of Kildare complained to none other than St. Patrick that women were being strung along by their beaus, waiting and waiting and waiting to be asked for their hand in marriage. Patrick took pity and decided that women could, indeed, ask men to marry them – on one day in February (with  an exception; see above) every four years.

What if the guy said no?

Well, this is the good part – if the woman was turned down in Denmark, she could score 12 pairs of gloves; in Finland, you could get material for a skirt. The government got the loot in Scotland where if a proposal was turned down, the man was fined. Also,  in England, the woman had to wear breeches or a scarlet petticoat when proposing.

What major events have  happened on Feb. 29?

On Feb. 29, 1504, Christopher Columbus, stranded in Jamaica, used a predicted lunar eclipse to frighten hostile natives into providing food for his crew.

On Feb. 29, 1692, the first warrants of the Salem witch trials were issued.

In 1984, Pierre Trudeau, Prime Minister of Canada, resigned.

On Feb. 29, 1940, Hattie McDaniel became the first black person to win an Oscar for her role in 1939's "Gone with the Wind."

Where is it observed?

Technically, everywhere on Earth, but Anthony, Texas, probably has the most elaborate celebration with  parades and birthday parties for leapers.

Check out Google's homage to leap year.