Every four years, an extra date appears on our calendars – February 29. This is because of the course of this time period, it actually takes about six hours longer for the Earth to orbit the sun than the ‘normal’ 365 days in a year.

To avoid getting out of sync, we have the extra day a Leap Year brings – and all of the weird and wonderful traditions that go with it.

Here are 10 strange Leap Year facts you may not know;

1. According to the Oxford English Dictionary, the term Leap Year derives from late Middle English and is “probably from the fact that feast days after February in any such year fell two days later than in the previous year, rather than one day later as in other years”.

2. A leap year is always divisible by four except at the beginning of a new century, when it is only a leap year if it is divisible by 400. For example, 2000 was a leap year but 1900 was not.

3. February 29 is known to be the date when women may propose to men instead of waiting for them to ask, as tradition has dictated. This convention is attributed through Irish history to St Patrick, who apparently granted the girl power.

4. According to ancient tradition, women either had to wear breeches or a scarlet petticoat to pop the big question.

5. People who marry on February 29 will only have to remember their wedding anniversary once every four years! However, in Greece, it is considered unlucky to marry at any time in a Leap Year.

6. In the last Leap Year – 2012 – Red Bull marked February 29 with some literal leaping when three base jumpers in three different US cities threw themselves off the top of buildings.

7.  There is a special club for babies born on February 29, who are known as Leapers, called The Honor Society of Leap Year Day Babies, which is based in America. It has more than 10,000 members from around the world.

8. Depending where you are in the world, Leapers have their birthdays in non-leap years on different days. In the UK and Hong Kong, a ‘Leaper’ who turns 18 in a non-leap year will legally become an adult on March 1. But in New Zealand, a Leaper’s official birthday is on February 28.

9. According to the Guinness Book of Records, the only verified example of a family producing three consecutive generations born on February 29 is that of the Keogh family. Peter Anthony was born on a Leap Day in 1940, while his son, Peter Eric, was born on February 29, 1964.

10. It’s bad news if you’re on an annual salary, as you’ll be working for free when February 29 arrives. However, people who are on an hourly rate will obviously get paid extra