5 Dates You Won't Find on Your Calendar

ThinkStock/Erin McCarthy
ThinkStock/Erin McCarthy

While you may be a bit fuzzy on which months have 30 days and which have 31, it’s safe to say you’re pretty familiar with the months and days of the year. But due to unusual record-keeping practices or because of months that were eliminated over the centuries, there are a few days you’ll never see on your joke-a-day calendar.

1. JANUARY 0

At midnight every New Year’s Eve, we go from December 31 to January 1. Simple, right? That’s how it works for everyone ... except astronomers. Each year, astronomers keep track of the movements of various planets and stars, which are compiled into what’s called an ephemeris. While it’s useful for things like space travel and positioning telescopes, GPS systems also use the data to properly function.

The thing about ephemerides (the plural of ephemeris) is that they don’t reference any year other than the one for which they were written. So if you had an ephemeris for the year 2000, you wouldn’t find any mention of 1999 or 2001. Generally speaking, it shouldn’t be necessary, though, since it’s only for that particular year anyway.

Except when you referenced January 1, that is. Because some more detailed ephemerides will list the previous day’s celestial positions for reference purposes, the ephemeris would have to have information for December 31. But, since the ephemeris doesn’t refer to any other year, this date will instead often be called January 0. Going back to our year 2000 example, an ephemeris for that year might list Prince’s favorite day, December 31, 1999, as January 0, 2000 instead.

It’s worth noting that many modern day ephemerides have dropped the use of January 0 entirely, but there are others that still use it.

And back in the 1920s, several groups lobbied for a calendar with 13 months, each with four weeks. To reach 365 days, their plan was to add "January 0."

2. FEBRUARY 30

You may have a friend or relative in your life whose birthday is February 29. Maybe they fudge it and celebrate on February 28 or March 1 every year, or possibly they just have a mega-party every four years. (Or they have a mega-party every year, because why not.) So imagine how frustrating it’d be to have been born in the Swedish Empire on February 30, 1712, the only day of its kind in history.

Naturally, it was a pretty complex set of events that led to February 1712 getting two leap days. Our modern, Western calendar is called the Gregorian calendar, which was developed under Pope Gregory XIII. It’s basically just a series of improvements to the Julian calendar, created by Julius Caesar.

While the Gregorian calendar was completed in 1582, adoption by many countries was slow, so it took over 100 years for the Swedish Empire (which was primarily Protestant and not Catholic) to adopt it. Because the Julian to Gregorian swap included a difference of ten days, many regions simply skipped their calendar ahead a week and a half. The Swedish Empire decided to roll out the difference more gradually, and intended to skip leap days for forty years, starting in 1700, until the calendar was finally correct.

Except that didn’t happen because, shortly afterward, war broke out and everyone forgot about the leap days until 1712, when Sweden’s King, Charles (or Karl) XII, declared that they would forget about the Gregorian calendar and just switch back to the Julian instead. Since they did manage to skip one leap day, in 1700 (which was a leap year under the Julian calendar, but not the Gregorian), they simply decided to add it back onto the calendar that February—meaning that February 1712 had two leap days according to Sweden’s calendar, which gave them the only February 30 in history. (Sweden finally went through with the Gregorian switch in 1753 and just skipped ahead a few days, like everyone else.)

3. MARCH 0

While you could think of February 30 as some weird kind of March 0, they’re not the same thing (though they do both involve leap years). If someone asked you what the day before March 1 is, you’d probably ask them, “What year?” March 0 is, like January 0, simply a reference to the day before it, but it’s useful since March 0 can be either February 28 or 29, depending on the year.

While this is occasionally used in software (some old versions of Microsoft Excel will accept 3/0 as a date and simply plug in the correct day for the particular year, for example), it’s more commonly found in something known as the Doomsday rule.

It sounds fairly ominous, but the Doomsday rule is just a method for calculating what day of the year falls on for any given date. For example, by following the Doomsday rule, you could quickly tell that January 19, 1481 was a Wednesday. How? By figuring out what creator John Conway calls “the Doomsday.” This is the day of the week that certain calendar days will always fall on in a given year. April 4, June 6, and August 8 are just a few days of the year that will always fall on that year’s Doomsday. Another big one? March 0, i.e., the final day of February.

So, using 1481 as our example again, you can use a formula to determine that its Doomsday was Monday. (For the record, 2013’s Doomsday is Thursday.) From there, we could quickly ascertain that March 0 was a Monday, and for that particular year, February only had 28 days (since it was not a leap year), making “March 0” Monday, February 28, 1481. If you’re mathematically-minded, it’s a fun challenge. If you’re not, well, you can always look the day up on the internet or use a Doomsday calculator.

4. UNDECIMBER AND DUODECIMBER

There aren’t just odd and unusual days of the year. There are entire months as well. Remember the episode of The Simpsons where the school ordered faulty calendars with a 13th month (called Smarch)? Well, as it happens, we kind of had that once upon a time—namely, those left over from the days of the Roman calendar, which preceded the aforementioned Julian calendar. Much like how the process of moving from the Julian calendar to the Gregorian calendar left a few odd days out, the move from the Roman calendar to the Julian one actually added some.

These days, 67 in all, were then added into a pair of months between the November and December of 45 BC, and were referred to as intercalaris prior and intercalaris posterior, which are often called Undecimber (pronounced like “oon,” not “uhn”) and Duodecimber in modern days.

These names refer to the fact that December is named after the Latin word for ten (which itself came from the fact that the Roman calendar originally only had ten months and not twelve), while the Latin words for eleven and twelve (or in this case, thirteen and fourteen) are undecim and duodecim.

What’s more, the terms have even come to be used in modern computing. The Java programming language includes support for a 13-month calendar, and it refers to the 13th month as Undecimber.

5. MERCEDONIUS

Speaking of the Roman calendar, by the time Julius Caesar came along, it hadn’t had ten months for quite a while. Nearly 600 years, in fact. The Roman calendar that Caesar reformed was itself a reformed calendar constructed by King (not Emperor) Numa Pompilius sometime in the 7th century BC.

Prior to Pompilius’ changes, the Roman calendar, as we mentioned, had ten months: Martius, Aprilis, Maius, Iunius, Quintilis, Sextilis, September, October, November, and December. (Quintilis was later renamed Julius after Julius Caesar himself, while Sextilis was changed to Augustus in honor of his son/grand-nephew, Caesar Augustus.) King Numa Pompilius added Januarius and Februarius, giving us the twelve months we have today … except he also added another, forgotten month that hasn’t been in use for millennia: Mercedonius.

Mercedonius was a kind of a leap month, situated between Februarius and Martius, and was approximately 27 days. Although there was apparently some kind of formula to determine in which years Mercedonius was used and in which years it wasn’t, the implementation was spotty, since it was up to whoever the current Pontifex Maximus was at the time to decide if the month was used or not.

Since the month was used so sloppily, Julius Caesar simply eliminated it entirely when constructing the Julian calendar, rearranged the days throughout the year, and made a simple, easy-to-follow leap day system.

The 10 Best Memorial Day 2020 Sales

iRobot,GoWise,Funko via Wayfair, Entertainment Earth
iRobot,GoWise,Funko via Wayfair, Entertainment Earth

The Memorial Day sales have started early this year, and it's easy to find yourself drowning in offers for cheap mattresses, appliances, shoes, and grills. To help you cut through the noise and focus on the best deals around, we threw together some of our favorite Memorial Day sales going on right now. Take a look below.

1. Leesa

A Leesa Hybrid mattress.
A Leesa Hybrid mattress.
Leesa

Through May 31, you can save up to $400 on every mattress model Leesa has to offer, from the value-minded Studio by Leesa design to the premium Leesa Legend, which touts a combination of memory foam and micro-coil springs to keep you comfortable in any position you sleep in.

Find it: Leesa

2. Sur La Table

This one is labeled as simply a “summer sale,” but the deals are good only through Memorial Day, so you should get to it quickly. This sale takes up to 20 percent off outdoor grilling and dining essentials, like cast-iron shrimp pans ($32), a stainless steel burger-grilling basket ($16), and, of course, your choice of barbeque sauce to go along with it.

Find it: Sur la Table

3. Wayfair

KitchenAid Stand Mixer on Sale on Wayfair.
Wayfair/KitchenAid

Wayfair is cutting prices on all manner of appliances until May 28. Though you can pretty much find any home appliance imaginable at a low price, the sale is highlighted by $130 off a KitchenAid stand mixer and 62 percent off this eight-in-one GoWise air fryer.

And that’s only part of the brand’s multiple Memorial Day sales, which you can browse here. They’re also taking up to 40 percent off Samsung refrigerators and washing machines, up to 65 percent off living room furniture, and up to 60 percent off mattresses.

Find it: Wayfair

4. Blue Apron

If you sign up for a Blue Apron subscription before May 26, you’ll save $20 on each of your first three box deliveries, totaling $60 in savings. 

Find it: Blue Apron

5. The PBS Store

Score 20 percent off sitewide at Shop.PBS.org when you use the promo code TAKE20. This slashes prices on everything from documentaries like Ken Burns’s The Roosevelt: An Intimate History ($48) and The Civil War ($64) to a Pride & Prejudice tote bag ($27) and this precious heat-changing King Henry VIII mug ($11) that reveals the fates of his many wives when you pour your morning coffee.

Find it: The PBS Store

6. Amazon

eufy robot vacuum.
Amazon/eufy

While Amazon doesn’t have an official Memorial Day sale, the ecommerce giant still has plenty of ever-changing deals to pick from. Right now, you can take $100 off this outdoor grill from Weber, $70 off a eufy robot vacuum, and 22 percent off the ASUS gaming laptop. For more deals, just go to Amazon and have a look around.

7. Backcountry

You can save up to 50 percent on tents, hiking packs, outdoor wear, and more from brands like Patagonia, Marmot, and others during Backcountry's Memorial Day sale.

Find it: Backcountry

8. Entertainment Earth

Funko Pops on Sale on Entertainment Earth.
Entertainment Earth/Funko

From now until June 2, Entertainment Earth is having a buy one, get one half off sale on select Funko Pops. This includes stalwarts like the Star Wars and Batman lines, and more recent additions like the Schitt's Creek Funkos and the pre-orders for the upcoming X-Men movie line.

Find it: Entertainment Earth

9. Moosejaw

With the promo code SUNSCREEN, you can take 20 percent off one full-price item at Moosejaw, along with finding up to 30 percent off select items during the outdoor brand's summer sale. These deals include casual clothing, outdoor wear, trail sneakers, and more. 

Find it: Moosejaw

10. Osprey

Through May 25, you can save 25 percent on select summer items, and 40 percent off products from last season. This can include anything from hiking packs and luggage to outdoorsy socks and hats. So if you're planning on getting acquainted with the great outdoors this summer, now you can do it on the cheap.

Find it: Osprey

At Mental Floss, we only write about the products we love and want to share with our readers, so all products are chosen independently by our editors. Mental Floss has affiliate relationships with certain retailers and may receive a percentage of any sale made from the links on this page. Prices and availability are accurate as of the time of publication.

12 Fascinating Facts About Queen Victoria

Photos.com/iStock via Getty Images
Photos.com/iStock via Getty Images

Much like Queen Elizabeth II, Queen Victoria was never expected to ascend to the British throne. Born on May 24, 1819, the young royal known as Princess Alexandrina Victoria of Kent defied all odds when she became Queen Victoria on June 20, 1837, less than a month after her 18th birthday.

Victoria ruled the United Kingdom of Great Britain and Ireland for more than 60 years, and in 1876 she adopted the title of Empress of India. Victoria didn’t oversee her empire alone, though. In 1840 she married Prince Albert of Saxe-Coburg and Gotha, and together they had nine children (including Victoria’s successor, King Edward VII). Here are 12 things you might not have known about Queen Victoria.

1. Queen Victoria was born fifth in line to the throne, which made her an unlikely ruler.

Princess Victoria and her mother in 1834
Princess Victoria and her mother in 1834.
George Hayter, The Print Collector/Print Collector/Getty Images

When Victoria was born, she was fifth in line to the throne, just behind her father, Prince Edward, Duke of Kent, who was fourth in line behind his three older brothers (none of whom had any living children—or at least no legitimate issue). Victoria's position in the line of succession placed her ahead of Ernest Augustus, Duke of Cumberland, her father's younger brother, which proved to be problematic.

When Victoria's father died on January 23, 1820, the future queen was barely eight months old. And when her grandfather, George III, died just a week later, the tot became third in line to the throne, which reportedly enraged Ernest Augustus. Fearing for the safety of her daughter, Victoria's mother chose to raise her away from the influence of Prince Edward's family—especially once rumors began to circulate that Ernest Augustus had designs on murdering his young niece to ensure that he, not she, would ascend to the throne. Whether or not there was any veracity to those rumors didn’t matter; on June 20, 1837, following the death of her uncle William, Duke of Clarence, 18-year-old Princess Alexandrina Victoria became Queen Victoria.

2. Queen Victoria was the first sovereign to rule from Buckingham Palace.

In 1761, Buckingham Palace was not yet a palace—it was simply a house. King George III bought the property for his wife, Queen Charlotte, to use as a family home. But when King George IV took over, he had bigger aspirations and decided to create an extravagant palace; costs ballooned to £500,000 (or more than $65 million in today's dollars). George IV died in 1830, however, which meant he never even got to live in the palace. When Queen Victoria took over in 1837, she became the first sovereign to rule from Buckingham Palace. In 1851, she was the first recorded royal to appear on Buckingham Palace’s balcony, a tradition the royal family still continues today.

3. Queen Victoria survived eight assassination attempts.

Queen Victoria sitting in a carriage car
Culture Club/Getty Images

Being in the public eye has its advantages and disadvantages, and for Queen Victoria that meant being the frequent target of assassination attempts. Over the course of her reign, she survived eight of them. In 1840, Edward Oxford shot at Victoria and Prince Albert while they rode in a carriage; Victoria, who was pregnant at the time, was thankfully not harmed. (Oxford was later judged to be insane.)

Two years later, John Francis attempted to shoot the couple not once, but twice—two days in a row. Again, neither was harmed. Just five weeks later, a teenager named John William Bean fired a pistol loaded with pieces of tobacco pipe at the Queen. In 1850, she was eventually injured when ex-soldier Robert Pate hit her over the head with an iron-tipped cane while she spent time in the courtyard of her home. Pate gave her a black eye and a scar that lasted for a long time.

4. Queen Victoria first met Prince Albert on her 17th birthday.

In May 1836, on Victoria’s 17th birthday, Prince Albert and the future queen—who were first cousins—met for the first time when Albert and his brother visited Kensington Palace with their Uncle Leopold. (Albert would turn 17 years old in August.) “He is extremely handsome,” Victoria wrote of the prince in her diary. But it would take almost four more years for the couple to tie the knot. And because royal rule stipulated that a reigning monarch could not be proposed to, Victoria had to be the one to pop the question. On October 15, 1839, Victoria proposed to Albert, who happily accepted. The couple married on February 10, 1840.

5. Queen Victoria popularized the white wedding dress.

Queen Victoria of England - Her Majesty 's wedding to Prince Albert in 1840
Culture Club/Getty Images

If you've ever wondered where the white wedding dress tradition originated, look no further than Queen Victoria. In 1840, Victoria wore an off-the-shoulder white satin gown covered in lace when she married Prince Albert. Though Victoria wasn’t the first royal to wear a white wedding dress—Mary, Queen of Scots wore white, too—wearing white became a status symbol following Victoria and Albert's nuptials.

6. Queen Victoria ensured that no other bride could replicate her wedding dress.

After Victoria’s wedding, she had the pattern to her dress destroyed so that no one could duplicate it.

7. Queen Victoria had nine children, but had some harsh opinions of motherhood.

Queen Victoria And Prince Albert With Five Of Their Children in 1846
Historica Graphica Collection/Heritage Images/Getty Images

Nine kids is a lot, and even though the Queen had a lot of help, she at times seemed indifferent to motherhood. In personal letters, she wrote about her children, mainly about their looks. She once wrote: “I am no admirer of babies generally—there are exceptions—for instance (your sisters) Alice, and Beatrice were very pretty from the very first—yourself also-rather so—Arthur too ... Bertie and Leopold—too frightful. Little girls are always prettier and nicer.” She also said “an ugly baby is a very nasty object.”

8. Queen Victoria was fascinated by Jack the Ripper.

In 1888, the serial killer known as Jack the Ripper began brutally murdering women—mainly prostitutes—in London’s Whitechapel district. Victoria received a petition signed by the women of East London urging the Queen’s “servants in authority” to “close bad houses” a.k.a. brothels, and passed it to the Home Office. When final victim Mary Jane Kelly was killed, Victoria contacted the Prime Minister and urged that better detectives be employed.

9. Queen Victoria’s grandson was suspected of being Jack the Ripper.

Prince Albert Victor, Duke of Clarence and Avondale, c1890s
The Print Collector/Print Collector/Getty Images

To this day, no one knows for sure who Jack the Ripper was. However, some people have theorized that Victoria’s grandson Prince Albert Victor was the killer. In the 1976 book Jack the Ripper: The Final Solution, author Stephen Knight wrote about how Victoria’s grandson might’ve contracted syphilis from a prostitute, which turned him mad. Another theory suggests the grandson secretly married a Catholic commoner and fathered a child, and it was the royal family who murdered the women to cover up the family secret. (Yes, that one seems a little far-fetched.)

10. Queen Victoria served as her grandson’s alibi.

Queen Victoria gave her grandson an alibi in her journal, thus exonerating him from accusations of being one of the world’s most famous serial killers.

11. Queen Victoria is the second longest-reigning British Monarch.

For 51 years, Victoria held the title of longest-reigning British monarch. But on September 9, 2015, Queen Elizabeth II took over the reins, so to speak, and bumped Victoria to second place. Victoria ruled for 63 years, 7 months, and 3 days; Elizabeth—who is Victoria’s great, great granddaughter—has ruled for almost 68 years.

12. Queen Victoria spent 40 years mourning the death of Prince Albert.

Queen Victoria with her great-granchildren at Osborne House, Isle of Wight, 1900
The Print Collector/Print Collector/Getty Images

A couple of years before his death, Prince Albert began experiencing stomach cramps, and he almost died in a horse-drawn carriage accident. He told Victoria his days were numbered: “I am sure if I had a severe illness, I should give up at once. I should not struggle for life. I have no tenacity for life,” he said.

On December 14, 1861, Albert succumbed to typhoid fever, though some people believe that stomach cancer and Crohn’s disease were the more likely culprits. Victoria blamed their son Edward for Albert’s death, as Albert was worried about a scandalous affair Edward was said to be having with an actress in Ireland.

Victoria lived for another 40 years and mourned Albert’s death the rest of her life by wearing black, becoming a recluse (she was often referred to as the Widow of Windsor), and keeping Albert’s rooms just the way he had left them.