Wednesday is February 29, a date that only comes around once every four years. Our list of 29 facts (plus a few folk tales) marks a remarkable point in the calendar.

1) A leap year is a year that contains one additional day, keeping the calendar year synchronized with the seasonal or astronomical year.  In the Gregorian calendar (the one commonly used in Scotland) February of a leap year will have 29 days instead of the usual 28.

2) It actually takes the Earth 365 days, 5 hours, 48 minutes, and 46 seconds to travel round the sun.

3) The ancient Egyptians developed the concept now described as a leap year as a solution to the problem of a year not  dividing into a precise number of days. However, it was the Romans who chose February 29th as the official date.

4) A leap year is also known as an intercalary or bissextile year.

5) A leap day now occurs in years that are evenly divisible by four, but not in years divisible by 100 unless the year is also divisible by 400.  Therefore 1800 and 1900 were not leap years, but 2000 was.

6) Leap years work slightly differently in the lunisolar Hebrew calendar. In that system a 13th lunar month is added seven times every 19 years.

7) Even with the extra day, February remains the shortest month, a fact that school children learn through a medieval English rhyme that ends "...all the rest have 31 except for February alone and that has 28 days clear and 29 in each leap year."

8) A person born on February 29th can be called a 'leapling' or a 'leaper'.

9) The chance of being born on leap day is about 1 in 1,461

10) Being born in on February 29th has the potential to create problems for leaplings, who will have been alive for almost eight decades before they enjoy their eighteenth birthday.

11) To avoid confusion, the law allows that someone born on February 29th will attain the age of 18 on March 1 of their eighteenth year.

12) Gilbert and Sullivan’s opera The Pirates of Penzance makes light of the misfortune of being born on February 29th through the plight of Frederic the pirate apprentice, whose indenture is until his 21st birthday rather than his 21st year.

13) According to astrologers, those born on February 29 (Pisceans) have unusual talents, including high levels of creativity and the ability to give sound advice.

14) Leaplings from history include Pope Paul III (born 1468) and the composer Gioacchino Rossini (born 1792). The notorious American serial killer Aileen Wuornos was born on February  29 1956.

15) High profile leaplings alive today include former Coronation Street star Wendi Peters, Darren Ambrose, the Crystal Palace midfielder, and the rapper Ja Rule.

16) Father and son James and Seamus Clarke, from Bristol, celebrate their eleventh birthdays just hours apart this week. James, whose turns 11 on February 28th, is just slightly ‘older’ than his 44-year-old dad.

17) Three consecutive generations of the Keogh family have been born on February 29th. Peter Anthony was born in Ireland in 1940, his son Peter Eric was born in 1964 and Eric’s daughter Bethany was born in 1996.

18) It is tradition for women to propose to prospective partners during a leap year. There is some debate over whether they have a whole year in which to pop the question, or must ask it on February 29th.

19) The tradition of women proposing is rumoured to have started in 5th century Ireland after St Bridget complained to Saint Patrick that women were waiting too long for a matrimony request.

20) An alternative theory claims the convention was enshrined in law by Queen Margaret of Scotland. She reportedly decreed that any man rejecting a woman’s proposal would need to pay the spurned party a fine of up to a hundred pounds, or give her a silk dress.

21) In order to give sharp-eyed potential suitors fair warning (and perhaps an opportunity to escape) a woman was required to wear red petticoats on the day of the proposal.

22) Similar folklore exists in Denmark, where leap day is marked on February 24. There, a man who turns down an offer of marriage customarily compensates the refused woman with 12 pairs of gloves.

23) In some countries, such as Greece, it is considered bad luck to get married in a leap year.

24) While leap day is not widely marked in Scotland, it is a cause of celebration in parts of the United States, where the public are encouraged to do something constructive with their ‘extra’ day.

25) A leap year festival is held every four years in Anthony, on the Texas/New Mexico border, which describes itself as ‘The Leap Year Capital of the World’. This year’s festival runs from February 25th to March 4th.

26) The romantic comedy Leap Year, about a would-be bride’s quest to propose to her elusive boyfriend starred Amy Adams and Matthew Goode. It was released in 2010 to tepid reviews.

27) More successful was the Leap Day William spoof on American television, which claimed that the character ‘Leap Dave’ visited children on Leap Day to trade their tears for candy.

28) In Britain, an extra day this year will mean an extra day of work with no remuneration for workers who receive a fixed annual salary. However, as there is an extra bank holiday in 2012 to celebrate the Queen’s Diamond Jubilee, most employees will end up working the usual number of days.

29) Feb 29th isn’t the only extra time added to the calendar. In 2008 an extra second was added to the end of the year.