A Day in Excess

The world is full of bizarre events and explanations. However, the one extra day of 2024 is not as bizarre as one might expect. There is fascinating science behind it.

Leap Day; Source: latenightparents

Time, a strange phenomenon, is almost out of our control, yet we perpetually attempt to grasp it in our hands. Since the beginning of civilisation, humans have sought to comprehend and define time to manage and remember the events around us. Essential for our lives, time greatly influences all social and historical phenomena. However, we did not always understand time as we do now.

The clearest and most apt understanding of time likely originated in 1582 when Pope Gregory XIII refined the Julian calendar, addressing its numerous issues. Among other adjustments, the Gregorian Calendar added an extra day to ensure uniformity in each year. This additional day, known as Leap Day, graces our lives only occasionally but plays a crucial role in maintaining the perfect alignment of our seasons over extended periods.

Leap Day is surrounded by myths, legends and even bizarre historical events seemingly tied to the day. Despite many superstitions associated with it, it is a completely scientific phenomenon. Removing the Leap Day from our calendars would quickly misalign the equinoxes and solstices, disrupting the harmony we’ve come to expect.

The scientific reasoning starts from a simple fact: a day on earth is not truly equal to 24 hours. It takes the Earth 23 hours, 56 minutes, and 4 seconds to complete one rotation on its axis. Additionally, the Earth revolves around the sun at the same time that it rotates on its axis. This creates a slight tilt in its axis. So, it rotates slightly extra to align toward the Sun from the same point as the previous day, maintaining the same relative position.

Interestingly, a day on Earth could be even less or more than 24 hours, evident in the varying times of sunrise and sunset throughout the year. The 24 hours presumed to be a day are just an average of many longer or smaller days that happen on Earth.

The same principle applies to years. At an astronomical level, a year is complete when the Earth completes a full revolution around the Sun, meaning it is the amount of time that the Earth takes to reach back the position it occupied with respect to the Sun. However, since the Earth also rotates on its axis at the same time, it takes 20 minutes less than the usual 365 days of our calendar.

If you bring all these facts together, you will encounter some fun mathematical numbers. A true calendar would have a year with 365.242188931 days! A 365-day calendar would put off our seasons in only a century. The Julian Calendar attempted to solve this problem by adding a leap day to every fourth year, accounting for the fact that every year has 365.25 days. We followed this calendar for more than 1600 years. It is quite there but not exactly right and soon the problems became too apparent.

In many countries like Italy, Poland, and Spain, some days in a year never came. In 1582, they had to skip October 5 through 15 to align themselves with the rest of the world. England did not skip those days until 1642, causing Isaac Newton’s birthday in England to shift to Christmas Day, while the rest of the globe celebrated Newton’s birthday on 4 January 1643.

The Gregorian calendar provided a simpler solution. Pope Gregory XIII defined that only years divisible by 4 should be leap years, with exceptions for years divisible by 100, unless they are also divisible by 400.

This new system gives us a year that is 365.2425 days long. This calendar would hold true for 3200 years, after which we might have to skip a Leap Day. The solution? Exclude all the years divisible by 3200 from having a Leap Day. Such a calendar would hold true for more than 700,000 years.

However, it will not be ever-lasting, and at one point in our future, we might need a yet new calendar. Every time an earthquake happens on Earth, it creates a slow-down effect, an average of 14 microseconds per year. Over millions of years, a day on Earth becomes longer. It is a slow process, and the fact that at the beginning of Earth’s time, a day was only 6-8 hours long seems unbelievable.

Owing to this, in the next four million years, there will be no need for a leap day or a leap year on Earth. It will take exactly 365 days to rotate around the Earth. If humans are still alive and living on Earth by that time, they might even have to work on a reverse Leap Day concept to keep things aligned. As for the present, the Leap Day cycle of the Gregorian calendar will work just fine.

One might ask, why February? For that answer, one might need to travel back to ancient Rome and meet Julius Ceaser and ask him this question. All we know is that the Julian calendar was inspired by the Egyptian solar calendar.

Despite the complex astronomical features behind this day, it is interesting to note that various cultures consider the day an anomaly. In Ireland, 29 February is the only day when women can propose to men, reversing traditional gender roles. Men can’t refuse the proposals, and if they do, they need to pay compensation. In Scotland, single men and women wear red attire on this day to attract suitors. Even witches come out to cause mischief.

Contrary to this, in Greece, the day is considered inauspicious, and no marriages take place on the Leap Day. In Africa, the Leap Day is seen as favourable for weddings. In Anthony, a town in the United States, the “Leap Year Capital of the World,” a grand celebration ensues on this day. Leaplings parade the streets among the many other activities that happen.

Amidst these quirky traditions and the science of the Leap Year, the Leap Day phenomenon is quite an interesting concept. It showcases how history, culture, and time converge, ensuring humanity’s place in the complex, vast, and huge universe and the nothingness that surrounds us. 2024 is yet another year in this cycle with an extra day in February.