A leap year occurs when a year has 366 days, instead of the usual 365.
In ancient Rome, the Romans used to follow a calendar that had 355 days in a year. This calendar eventually became out of sync with the seasonal changes and it made it difficult to celebrate festivals at the same time each year. They tried adding a 22 day month to every second year so as to keep festivals occurring around the same time period each year, but their Roman ruler, Julius Caesar, decided to make things simpler by adding days to different months of the year to create what we now know as the 365 days calendar.
To be specific, the actual length of a year is 365.242 days, not 365 days. Because of this, every 4 years (or years that can be divided by 4) will result in an extra day. This extra day will be added to the calendar as February 29th, and the year will become known as a leap year.
Ever wondered why February is shorter than every other month?
This is because of Augustus, the Roman ruler to come after Julius Caesar. The Roman government named the month of August after Augustus to honour him, but the month was only 30 days long. Julius Caesar's month of July had 31 days, and it wouldn't look good on Augustus to have a shorter month than Caesar!
To make August as long as July, they borrowed a day from February. This permanently reduced February to only 29 days during a leap year, and for every other year - only 28 days.
The "extra day" problem
Having an extra day in February can be somewhat problematic. For example, if you are an employee being paid a monthly salary, you essentially are working an extra day for free during a leap year. But if you are being paid per hour, you literally have an extra payday.
There has also been cases of criminals convicted to prisons suing the government for "miscalculating" the length of their prison sentences because they had failed to consider the additional days they had to serve on account of the leap years. Good thing most, if not all, of the cases were thrown out of court as it is worth noting that the prison sentences go by number of years, regardless of how long or short each year may be.
Similarly, I bet it sucks to be born on February 29. You only celebrate your birthday once every four years! Or you can use it as an excuse to throw the most lavish celebration ever since it occurs so rarely.
The leap year mother and daughter
On February 29, 2008, Michelle Birnbaum from New Jersey gave birth to her daughter, Rose. The coolest part about this story? Michelle herself was also born on February 29, making both mummy and baby both leap year babies!
The odds of someone being born on February 29 are 1 in 1,641. However, the odds of both a mother and daughter sharing that same birthday of February 29 are 2 million to 1!
That definitely makes it a birthday worth celebrating!