2016 is a leap year, with 366 days instead of 365. But do you know that leap years happen after every four years?
Here are 10 facts you may not know about leap year…

1. The leap year’s extra day is vital because a complete orbit around the sun takes slightly longer than 365 days – 5 hours, 48 minutes, and 46 seconds longer, to be exact. At one time people observed a 355-day calendar with an extra 22-day month every two years. But in 45BC Julius Caesar ordered his astronomer, Sosigenes, to simplify things. So Sosigenes opted for the 365-day year with an extra day every four years to use up the extra hours. The extra day is added to February because it used to be the last month of the Roman calendar.

2. The system was then fine-tuned by Pope Gregory XIII. He coined the term “leap year” and declared that a year that is divisible by 100, but not by 400, is not a leap year. So 2000 was a leap year under the Gregorian calendar, as was 1600. But 1700, 1800 and 1900 were not.

3. The tradition of women proposing on leap day dates back to fifth-century Ireland when St Bridget complained to St Patrick that women had to wait too long for suitors to propose. He then gave women a single day in a leap year to pop the question – the last day of the shortest month. Legend has it that Brigid then dropped to a knee and proposed to Patrick that instant, but he refused, kissing her on the cheek and offering a silk gown to soften the blow.

4. Queen Margaret of Scotland was apparently five-years-old when she came up with the notorious February 29 proposal trap. If a man did refuse the proposal, he would be fined a kiss, a silk dress or 12 pairs of gloves.

5. Women either have to wear breeches or a scarlet petticoat to pop the question, according to tradition.

6. One in five engaged couples in Greece will plan to avoid getting married in a leap year. They believe it is bad luck. In Italy legend has it that women are erratic during a leap year and several proverbs warn against planning important life events in a leap year. “Anno bisesto, anno funesto” means “leap year, doom year”.

7. People born on February 29 are called “leaplings” or “leapers”. The chance of being born on a leap day is one in 1 461. There are five million leaplings around the world.

8. In Russia it is believed a leap year is likely to bring more freak weather patterns and a greater risk of death all round. Farming folk say beans and peas planted in a leap year “grow the wrong way”.Scottish farmers believe leap years are not good for crops or livestock, thanks to the old proverb: “Leap year was ne’er a good sheep year.”

9. Workers paid fixed annual or monthly salaries essentially work for free on February 29 because wages are not usually calculated to account for the extra day. And prisoners with one-year sentences must serve the extra day if the term crosses leap day.

10. For centuries, astrologers believed children born on leap day have unusual talents, unique personalities and even special powers. The poet Lord Byron was born on a leap day, as well as rapper Ja Rule and footballer Darren Ambrose.