7 Different Calendars Humans Have Used Throughout History

Wait, what date is it really? How we gauge our sense of time hasn't always been so consistent. 

What’s the date? With smart phones able to tell us at an instant, you probably had the answer within a second or two. But have you ever thought about what that date means? Why we measure time the way we do? You almost certainly use the Gregorian calendar, but what else is there?

Here are some different methods of measuring time throughout history. Some were popular, others just ideas. All of them present new ideas about when we are, and why.

 1.      Julian Calendar

The original calendar used in Europe and named for Julius Caesar, who introduced it. While basically similar to the modern Gregorian calendar, it was replaced in most of Europe when it was found to be too inaccurate for religious purposes. It took several hundred years for it to be totally phased out. Russia only rejected it in 1918. It is still referenced, on rare occasion, by the Russian Orthodox church.

2.      The French Republican Calendar

An invention of Revolutionary France. It was designed not only to reflect the metric love of decimal systems but also to drive out the influence of the Church and monarchy in timekeeping. The system featured a 10-day week and 12 months of 30 days. The remaining five or six days would serve as a week of national holidays at the end of the year. While never popular, the calendar did last 14 years before France returned to the Gregorian calendar. Catholic feast days were replaced with special designations for each day of the year, celebrating things from wheat to human reason.

3.       The Soviet Calendar 

Taking a page from the French playbook, the Russians also created a new system of measuring time after the creation of the Soviet Union. This calendar was designed to keep output levels high, as well as drive out religious influence from Russian life. Featuring a five-day week, workers were given color-coded designations for days off. While this did allow for 80 percent of a factory’s labor force to always be present, no attempt was made to allow for common days off with family or friends. The calendar was altered and later abandoned due to unworkability. 

4.      The Traditional Chinese Calendar

Used in traditional Chinese homes for knowing both holidays and the best dates for special events. Various forms of this calendar were used officially in China up to the 20th century. The final version of it was lunisolar, and designed by both Chinese scholars and Jesuit missionaries. While no longer used officially, it’s lunar determination of holidays is still the basis for major Chinese events.

5.       Hijri calendar

A traditional lunar calendar used alongside the Gregorian calendar by many Islamic nations. Starting with the year of the emigration of Muhamad to Medina, meaning 622 AD is the year one. As a lunar calendar which starts a day at sundown, it is possible to have differing dates in differing parts of the world. This causes a particular headache at Ramadan. The current year by this calendar is 1439 AH (latin for Anno Hegirae, "in the year of the Hijra"), and it will spans (approximately) from 21 September 2017 to 10 September 2018.

 6.      Holocene calendar

Designed by Cesare Emiliani in the 1990s, this calendar places the year zero at the point where the first permanent man-made structures went up. The conversion is a simple addition of 10,000 to the Gregorian year. This calendar, while little more than a curiosity, was designed to be applicable to all peoples across cultures while also revealing to us how long human history has been. The Gregorian calendar we use is counted from the birth of Jesus. The Holocene calendar places year zero on what is, objectively, noteworthy to all humans. An excellent video explaining this idea can be seen here.

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Here's the science of black holes, from supermassive monsters to ones the size of ping-pong balls.

  • There's more than one way to make a black hole, says NASA's Michelle Thaller. They're not always formed from dead stars. For example, there are teeny tiny black holes all around us, the result of high-energy cosmic rays slamming into our atmosphere with enough force to cram matter together so densely that no light can escape.
  • CERN is trying to create artificial black holes right now, but don't worry, it's not dangerous. Scientists there are attempting to smash two particles together with such intensity that it creates a black hole that would live for just a millionth of a second.
  • Thaller uses a brilliant analogy involving a rubber sheet, a marble, and an elephant to explain why different black holes have varying densities. Watch and learn!
  • Bonus fact: If the Earth became a black hole, it would be crushed to the size of a ping-pong ball.

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Military recruits are supposed to be assessed to see whether they're fit for service. What happens when they're not?

Flickr user Tommy Truong79
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  • During the Vietnam War, Robert McNamara began a program called Project 100,000.
  • The program brought over 300,000 men to Vietnam who failed to meet minimum criteria for military service, both physically and mentally.
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Credit: EAST Team
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