Tomorrow is that rarest of days, so here is the recipe for the Leap Day Cocktail invented by pioneering bartender Harry Craddock at the Savoy Hotel. The 1930 Savoy Cocktail Book claims: ‘it is said to have been responsible for more proposals than any other cocktail ever mixed’, and you can make your own Leap Day cocktail with Craddock’s original recipe: 2 ounces gin; ½ ounce Grand Marnier; ½ ounce sweet vermouth; 1 dash fresh lemon juice, shake, serve, garnish with a lemon peel.

So pour yourself a cocktail as CabbieBlog gives you 29 leap year facts:

① Today is the sixth leap day of the 21st century

② There are only 24 leap years this century because 2100 won’t be a leap year (ditto 2200, 2300, but not 2400)

③ Leap year babies celebrate their birthday only once every 1461 days

④ You have a 1 in 1,461 chance of being born on 29 February. The odds are a lot higher if your parents have sex on 29 May the previous year

⑤ Over a 400 year period, the odds of being born on 29 February lengthens to 1 in 1,506

⑥ About 40,000 people in the UK are leap day babies, about 4 million people worldwide are leap day babies

⑦ The Queen sent no centenarian birthday telegrams on 29 February 2000, because there was no 29 February 1900

⑧ Today is the 515th leap day to be observed since the first in 45BC

⑨ Leap years occur every four years. They’re required because a solar year is almost exactly 365¼ days long, and over a four year period those four quarter-days add up to make one whole extra day

⑩ The composer Rossini was born on 29 February 1792, Pope Paul III on 29 February 1468, and actor Joss Ackland on 29 February 1928

⑪ If you have a leap year birthday you have to decide when to celebrate it in non-leap years – 28 February or 1 March, in legal situations, UK law dictates 28 February

⑫ The Gilbert & Sullivan operetta The Pirates of Penzance revolves around a 29 February birthday. Frederic is a pirate’s apprentice, free to return to respectable society on his 21st birthday, except that at the age of 21 he realises he still has 63 years to go. A leap child’s lot is not a happy one

⑬ Tomorrow is the first leap day to fall at the weekend since 2004, the first Sunday will occur in 2032

⑭ The first thirteen leap years were 45BC, 42BC, 39BC, 36BC, 33BC, 30BC, 27BC, 24BC, 21BC, 18BC, 15BC, 12BC and 9BC. At this point, Roman priests spotted they’d been adding leap years every three years, rather than every four as Caesar decreed, so all leap years were temporarily suspended. They restarted in 8AD, after which they continued every four years as intended

⑮ Exactly 500 years ago today, Christopher Columbus pulled off his great eclipse trick. A leaky ship forced him to land on the beach in Jamaica, and he and his crew rapidly ran out of supplies. Fortunately, Columbus knew his astronomy and realised that a total lunar eclipse was due on 29 February 1504. He gathered the local natives together at sunset and told them God was displeased and would eat up the Moon. The eclipse started, the natives were sore afraid, and Columbus eventually agreed to ‘return the Moon’ in return for food

⑯ Leap years are quadrennial, like the Olympics or the World Cup

⑰ Leap day is also St Oswald’s Day, named after a 10th-century archbishop of York who died during a feet-washing ceremony on 29 February 992. His feast is celebrated on February 28th during non-leap years

⑱ When Julius Caesar introduced leap years the extra day wasn’t 29 February, it was February 24th. The Romans repeated the sixth day before March 1st, or “dies bissextus”, and leap years are still sometimes called bissextile years

⑲ Leap Day number ones over the past years would make a fascinating compilation: Dean Martin (Memories are made of this, 1956); Anthony Newley (Why, 1960); Cilla Black (Anyone Who Had A Heart, 1964); Esther & Abi Ofarim (Cinderella Rockefella, 1968); Chicory Tip (Son Of My Father, 1972); Four Seasons (Oh What A Night, 1976); Blondie (Atomic, 1980); Nena (99 Red Balloons, 1984); Kylie Minogue (I Should Be So Lucky, 1988); Shakespear’s Sister (Stay, 1992); Oasis (Don’t Look Back In Anger, 1996); All Saints (Pure Shores, 2000); Peter Andre (Mysterious Gril, 2004); Duffy (Mercy, 2008); Gotye (Somebody That I Used To Know, 2012); and Lukas Graham, not 4 but (7 Years, 2016)

⑳ IT-type people feared computers might go wrong on Leap Day 2000, misinterpreting the date as 29 February 1900, a date which didn’t exist. They were wrong

㉑ Leap year babies endured seven consecutive years with no birthdays from 1897 to 1903, and will again from 2097 to 2103

㉒ Every leap year the town of Antony on the Texas/New Mexico border holds a Leap Year Festival

㉓ Brothers and sister Heidi, Olav and Leif-Martin Henriksen of Stavanger, Norway were all born on 29 February – in 1960, 1964 and 1968 respectively

㉔ There has, just once, been a February 30th. It happened in Sweden, and it happened in 1712. The Swedes needed to lose 11 days to come in line with the Gregorian calendar, but forgot to miss out 29 February in 1704 and 1708 so had to add an extra leap day in 1712 to get back in sync. Pity the Swedish babies born on February 30th 1712, because they never saw another birthday

㉕ The Academy Awards have twice been awarded on 29 February – in 1940 (best picture: Gone With The Wind) and 2004 (best picture: Lord of the Rings III)

㉖ In any 400 year period, there are 97 leap years, after which the calendar repeats. The most likely days of the week for 29 February to fall are Monday and Wednesday. The least likely are Sunday, Tuesday and Thursday

㉗ Sir James Wilson, former Premier of Tasmania, was born on 29 February 1812 and (unbelievably) died on 29 February 1880 – his 17th birthday

㉘ Leap year rules make the Gregorian calendar accurate to 1 day every 3236 years. But far better is the modern Iranian calendar (eight leap days inserted into a 33-year cycle) which is accurate to 1 day every 110, 000 years

㉙ In the Chinese calendar, a leap month is inserted if there are 13 moons from the start of the 11th month in one year to the start of the 11th month in the next year