Calendar mysteries

How are we closer to the Sun during winter? 10 calendar surprises

Most of us think we know the calendar pretty well, and if we don’t, our phones are there to remind us of dates and events. But the way humans measure the passage of time hasn’t always been the same. From the origins of month names to the truth behind leap years, today we’re going to share 10 surprising facts you probably didn’t know about the calendar.

The probability of being born on February 29 is 1 in 1,461. Although birthdays on this date are rare, people born on it even have a name: leaplings. Leaplings officially get to celebrate their birthday on February 29 only once every four years, but what happens in the other years? While some people prefer not to jump to another month, March 1st is considered more astronomically accurate, as it comes directly after February 28.

The Earth’s orbit is elliptical, which means there are times when we are closer to the Sun and other times when we are farther away. In January, Earth is at its closest point to the Sun, known as "perihelion." You might wonder how we can be closer to the Sun during winter, but the seasons are caused by Earth’s tilt, not by our distance from the Sun. On the other hand, the month when we are farthest from the Sun is July, and this point in the orbit is called "aphelion."

Due to its particularly short duration, February is the only month that can lack a full moon. Lunar cycles are 29.5 days long, which means that, approximately every 19 years, February has all the lunar phases except the full moon. When this happens, both January and March have two full moons, with the second one being called a "Blue Moon"; and that's why, when we say "once in a blue moon," we're talking about something that happens very rarely. The next time this will happen will be in the year 2037.

Did you know that our calendar has a name? That’s right; most of the world uses the Gregorian calendar, named after Pope Gregory XIII, who introduced it in 1582 as a reform of the older system.

The main difference lies in how leap years are handled. The previous system, known as the Julian calendar, added a leap year every four years, assuming a year lasted exactly 365.25 days. However, a real solar year is slightly shorter. To fix this, the Gregorian calendar keeps leap years every four years with one exception: century years (like 1900) are not leap years unless they are divisible by 400 (such as 2000).

But before the Julian calendar, ancient Rome used an even older system with one key difference: it had only 10 months. This calendar began in March and ended in December, totaling just 304 days. What about the remaining days? They were considered a winter gap and simply weren’t counted. Around 700 BC, January and February were added to fill that gap, and these changes were later standardized under Julius Caesar’s reform in 45 BC, when he introduced the Julian calendar.

The names also come directly from life in ancient Rome, where months were named in honor of deities and important festivities. For example, March was named Martius after Mars, the god of war, because it marked the start of the military campaigning season. Aprilis, the Roman name for April, comes from the Latin verb aperire, meaning "to open," in reference to the arrival of spring. May was named Maius after Maia, the goddess of fertility and growth, and June was named Iunius in honor of Juno, the Roman goddess of marriage.

What about the rest of the months? From July through December, they were originally named after their position in the year. Since March was considered the first month, July was called Quintilis ("the fifth"), August was Sextilis ("the sixth"), September comes from septem, meaning "seven" in Latin, October from octo ("eight"), November from novem ("nine"), and December from decem ("ten").

Most of these names remained similar, with two exceptions: Quintilis was renamed Iulius to honor Julius Caesar after his death, and Sextilis became Augustus, in honor of Augustus Caesar, the first Roman emperor.

The days of the week are no exception to Roman tradition. Sunday was named dies Solis ("day of the Sun"), Monday was dies Lunae ("day of the Moon"), Tuesday was called dies Martis (day of Mars), Wednesday dies Mercurii (day of Mercury), Thursday dies Iovis (day of Jupiter), Friday dies Veneris (day of Venus), and finally, Saturday was dies Saturni (day of Saturn).

As you may have noticed, only Saturday retained its Roman root, while Sunday and Monday kept their meaning but were translated. What happened to the rest? They were influenced by Norse mythology, resulting in Tuesday being named for Tyr, a Norse god of war; Wednesday after Woden (Odin), the Norse interpretation of Mercury; Thursday from Thor, the god of thunder, replacing Jupiter; and Friday from Freya, a Norse goddess linked to the Roman Venus.

In the United States, Sunday is considered the start of the week. This tradition has religious and cultural roots, and it’s shared by many parts of the world, but not all of them. In fact, several other English-speaking countries do it differently: places like England, Australia, and parts of Canada consider Monday the first day of the week, with Sunday closing it out.

Facts you didn't know you needed

Is the day longer for your pet? Mind-blowing facts you need to know

Adults often assume they already understand the world, but there’s always something new to surprise us! Did you know that clouds actually have weight? Or that the day is longer for some animals? And that’s just the beginning. From hidden functions of your organs to the true color of the universe, today you’ll learn 10 fascinating facts you probably never thought to ask, but will make you sound impressively smart in your next conversation!

Unlike humans, animals don’t experience a shared "present" in quite the same way. Instead, their sense of time is tied to the rhythms of their own bodies. For very small animals with fast metabolisms like parrots, hamsters, or guinea pigs, time actually seems to pass more slowly. In a sense, they live in slow motion because their faster-working nervous systems allow them to process sensory information at a fast speed.

What if someone commits a crime and tries to blame their identical twin? Have you ever wondered about that? It’s a valid question; after all, identical twins not only look alike, they also share the same DNA. But here’s the surprising part: if investigators check fingerprints, the innocent twin could be cleared. That’s because, despite their nearly identical DNA, twins have unique fingerprints, shaped by subtle genetic and environmental factors in the womb.

You’ve probably spent time lying on the grass, watching clouds drift across the sky. They look light, fluffy, almost like cotton candy, and it’s hard to imagine them as heavy objects. But the truth is surprising: clouds are incredibly heavy. An average cumulus cloud can weigh around 1 million pounds! That impressive weight comes from the billions of tiny water droplets suspended in the air. So, how do they float? It’s because each droplet is extremely small and falls very slowly, while rising warm air currents help keep the cloud suspended above us.

Most of us have a rough image of the world map in our minds. But we have something to tell you: most maps aren’t completely accurate. Because the Earth is a sphere, cartographers have to distort some areas to represent it on a flat surface. On Mercator projection maps, countries near the poles appear much larger than they really are, while countries near the equator look smaller in comparison. For example, Alaska looks about the same size as Brazil, but in reality, Brazil is nearly five times larger!

Most people don’t realize that there’s actually a name for the color of the universe. Strange, right? But it’s true! Astronomers who studied the light from thousands of galaxies discovered that if you blend all the colors from the observable universe, the result is a soft, beige-ish white shade, famously named "Cosmic Latte" in 2002.

With 50 states, there’s no shortage of variety in their names. Almost every letter of the English alphabet appears at least once, except for one: Q, which is completely absent. In addition to this, there’s another surprisingly rare letter: J. While it isn’t entirely missing like Q, it only appears in one state, New Jersey.

Although we don’t notice it, indeed, the Earth’s rotation is gradually slowing. This happens because tidal friction, caused by the Moon’s gravitational pull on our oceans, creates a subtle drag on the planet’s spin. As a result, days are getting longer, but very gradually: by only about 1.7 milliseconds per century.

Do you remember your last dream? Whether good or bad, dreams are a constant part of sleep, but not everyone experiences them in the same way. Deaf people who use sign language in their daily lives often communicate through signs in their dreams, too. Meanwhile, blind people tend to have dreams rich in sounds, smells, and tactile sensations, using these other senses to experience the dream world.

We’re used to seeing hippos covered in mud, splashing in water, or barely peeking above the surface. But here’s a surprise: hippos can’t actually swim! That’s right. Because of their huge, heavy bodies, they don’t float or paddle like most animals. Instead, they walk or run along the riverbed.

Can your brain really "eat" itself? Well, close, but not exactly. There’s a process called phagocytosis, carried out by specialized immune cells in the brain known as microglia. These cells engulf and remove debris, dead cells, and other unwanted material. But don’t worry; it’s safe! The mechanisms exist to protect, repair, and maintain your brain.