What is the common denominator between the current year 2024 and the following years: 2028, 2032, 2036, 2040, and 2044? These are years that will witness presidential elections in the United States, and during which the Summer Olympics are scheduled to be held, but what is certain is that they will be leap years, as the month of February increases by an additional day to become 29 days, but why?
The 24 hours added approximately every 4 years to the shortest month of the year, also known as a “leap day,” is a subtle acknowledgment that even something as mundane and simple as a calendar can be more complicated than we think, so while you're making plans for an extra day to arrive to your goals this year, here's a quick guide on how to make it happen.
Unidentified workers pick green beans in a field
Why do we have a leap year?
Man-made calendars generally have 365 days, and "simple years" loosely define the number of days it takes the Earth to complete one revolution around the sun, known as a solar or tropical year that affects the seasons, but 365 days is actually a rounded number.
It takes the Earth 365.242190 days to revolve around the Sun, or 365 days, 5 hours, 48 minutes, and 56 seconds. This "astronomical" year is slightly longer than the calendar year, and this fraction or the extra five hours, 48 minutes and 56 seconds must be accounted for somehow.
Although 0.2422 of a day may seem insignificant, over decades and centuries the loss of a quarter of a day per year can accumulate. To ensure that our calendar years agree with Earth's astronomical year, it is necessary to add a day periodically to make up for lost time and for the four seasons to always occur at the time we expect them to occur each year.
Ignoring this small number ultimately means that the months in which we usually experience all four seasons will change, that is, they will not fall in the same months every year, and this would affect other aspects of life. For example, your school year may start in the spring instead of late summer.
Over the course of 120 years, this will lead to a delay of an entire month, and thus the calendar will not match the seasons, and this in turn will lead to chaos in critical aspects of human projects, the most important of which is agriculture, as farmers will face greater difficulty in planting and harvesting crops, which may affect food supplies.
If we do not take this additional time into account, the results could be disturbing, if not devastating, because in about 700 years the summer we expect in June in the Northern Hemisphere will begin; In December, hundreds of years from now we will be celebrating New Year's in 90 degree weather.
Imperfect calendars
History does not accurately record which ancient culture was the first to notice the inaccuracy of the Earth's orbit, but over the centuries many cultures - including Hebrew, Chinese, and Buddhism - have tried to create calendars, but they have not always succeeded in implementing them correctly.
The Sumerians - who lived about 5,000 years ago in what are now Iraq and Kuwait - divided the year into 12 months, each consisting of 30 days, making their 360-day year shorter than the Earth's annual journey around the sun. When the Egyptians adopted this calendar, they solved the problem by adding 5 days for parties at the end of the year.
The ancient Egyptians - before about 3100 BC - and other cultures from places like ancient China and Rome used it; In lunar calendars, they tracked months by how long it took the moon to orbit the Earth, but lunar months are about 29.5 days long (lunar years are only about 354 days), causing an 11-day gap between the calendar and the seasons.
Due to this natural gap, such calendars periodically required the addition of additional months, known as intercalary months, to keep them on track. However, these months were not necessarily regular.
Historians are still unclear about how the early Romans kept track of their years. The early Roman calendar, in the 8th century BC, appears to have consisted of only 10 months, plus an unspecified winter period, the length of which meant that the calendar was not linked to the solar year.
Eventually, this uncertain time period was replaced by the new months of January and February, which were the last months of the year and had fewer days, but the situation remained complicated.
In ancient Rome, their calendar was diverse, and included an intercalary month consisting of 23 days known as “Ercedonius” to account for the difference between the Roman year and the solar year, but it was not an independent month, as it was included not among the months of the year, but during the month of February for reasons that may be Associated with lunar cycles.
To make matters even more confusing, the decision to include or drop the month of Mercedonius often fell to the consuls (the highest ranking in the Roman Empire), who used their ability to shorten or extend the year to achieve their own political goals. As a result, by the time of the Roman Emperor Julius Caesar, the Roman year and the solar year were completely out of sync.
Where did leap day come from?
It is clear that Mercedonius' regime angered Caesar, who became consul general and then became dictator of Rome (the word dictator in ancient Rome means a ruler with broad powers), so he radically changed the course of European history, in addition to the conquest of Gaul and the transformation of Rome from a republic to an empire. Caesar arranged the Roman calendar to align with the sun.
While Julius Caesar is often credited with creating the scheme that much of the world still uses to this day, he was inspired by the Egyptians. During his time in Egypt he became convinced of the superiority of the Egyptian solar calendar, which included a 365-day year with A month intercalated transversely to correct the calendar.
Caesar added an additional two months to the year 46 BC to make it 445 days instead of 365 to compensate for the missed insertions, and the Julian calendar entered into force on January 1, 45 BC.
He also made an important amendment when he made the year consist of 365.25 days (which is slightly longer than the solar year 365.2422), adding a new day every 4 years. In keeping with the Roman tradition of playing around with the length of the month of February, that day falls in the second month of the year, and thus the leap day was born.
This method would continue over several centuries, but it did not pass without problems. Although the Julian calendar was close, it was not correct, and did not fully take into account the differences. The small difference between 365.25 and 365.2422 made each calendar year shorter by about 11 minutes. From the seasonal calendar, this means that the Julian calendar will be short by one day every 128 years.
By the 16th century, times had changed again, and this was a problem for the Catholic Church, as major dates and holidays changed from their traditional date, including Easter. The holiday was supposed to fall on the first Sunday after the first full moon or after the vernal equinox. At that time, the date of Easter had changed by about 10 days.
To fix this problem, Pope Gregory
He also developed a new leap year system that uses the solar year of 365.2422 days, added one leap day every four years, and set February 29 as the official date, but took into account the inaccuracy of canceling this day during centennial years that are not divisible by 400. To keep calendars from drifting.
It may seem confusing, but this system has kept the calendar and seasons in sync for more than 400 years. Experts point out that although the Gregorian calendar is accurate for the solar year (365.2425 days), it is not perfect, as there is still a 30-second deviation every year, and thus it will be necessary to make another correction.
Fortunately, the Gregorian calendar is as short as the Julian calendar by one day every 128 years; It only varies by about one day every 3,030 years, so humanity has some time before this becomes a problem.
Being born on a leap day
Leap Day was associated with cultural traditions and superstitious beliefs, and oddly enough, many of the customs of this day revolved around romance and marriage. One of these customs is “Singleness Day,” an Irish tradition dating back to the fifth century, when Saint Bridget expressed her regret to Saint Patrick for not allowing women to propose to men.
Legend has it that Saint Patrick set the only day that does not come every year, February 29, as the day on which women were allowed to propose marriage to men.
This tradition moved across the Irish Sea to Scotland and England, where the British added a new twist. If a man rejected a woman's proposal, he owed her several pairs of beautiful gloves, perhaps to hide the fact that she was not in a relationship.
However, in Greek tradition, marrying on a leap day is considered bad luck, and statistics show that Greek couples continue to take this superstition seriously.
After thousands of years, birth on a leap day (February 29) has become special. However, at least 5 million people celebrate their birthday on this day around the world, and their odds of being born on a leap day are about 1 in 1,461.
A normal year has 52 weeks with one day, meaning that if your birthday falls on a Monday one year, the next year it should fall on a Tuesday. However, adding a day during a leap year means that your birthday now "jumps" by more than one day. Instead of your birthday being on Tuesday as is the case after a normal year, your birthday during a leap year will fall on Wednesday.
If you were born on a leap day, that means you were born on the rarest day anyone can have, in which case you may only have an excuse to celebrate your actual birth date once every four years.
In years without leap days, you have to decide whether to celebrate your birthday on February 28 or March 1 during a typical 365-day year, and you will continue to grow older like the rest of us.
Good to know!
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