Ancient & Modern Calendars - The Calendar Issue



Reading Comprehension Activity

Read the article and answer the questions below.


Ice-age hunters in Europe over 20,000 years ago apparently scratched lines or made holes in sticks and bones. Historical accounts state that Sumerians, 5000 years ago, had a calendar with 30 day months. Stonehenge, built over 4000 years ago in England, had alignments which determined eclipses, solstices and so on. To name just a few examples. Archeologists usually discover that in every culture, some people were preoccupied with measuring and recording the passage of time.

The Egyptians, for one, realized that the "Dog Star" or Sirius, rose next to the sun every 365 days, about when the annual inundation of the Nile began. Based on this knowledge, they devised a 365 day calendar that seems to have begun around 3100 BCE.

Before 2000 BCE, the Babylonians used a year of 12 lunar months, giving a 354 day year. In contrast, the Mayans of Central America relied not only on the Sun and Moon, but also the planet Venus, to establish 260 day and 365 day calendars.

The solar calendar used by most of the world today is known as the Gregorian calendar. Named after Pope Gregory XIII, who introduced it in 1582, this modern calendar is the end result of hundreds of years of fine-tuning. It was developed from the Julian calendar, which was created in 46 BC by Julius Caesar.

The Julian calendar was also a solar calendar, based on the time it takes for Earth to travel one complete loop around the sun. In Julius Caesar’s time, although astronomers believed that the sun revolved around Earth, they still managed to make fairly accurate measurements of the length of a complete cycle. A solar year, they calculated, was about 365.25 days long. Julius Caesar, deciding that it would be difficult to add ¼ of a day onto each year, ordered one extra day to be added every four years to the month of February, creating what would be called “leap” years. This calendar was used by the western world for over a thousand years.

Unfortunately, there was a problem with the Julian calendar. When Julius Caesar ordered a leap year every four years, he was putting in too many extra days. A solar year is not 365.25 days long, but in fact 365.24219 days. The difference between the actual length of the solar year and the approximated value is very small, but over several hundred years it began to add up. By the 1500s, spring holidays were starting to happen in the summer.

In 1582, Pope Gregory XIII came up with an idea of how to fix the problem. He realized that there were too many leap years in the Julian calendar, so hereorganized it into a more complicated system. In the new calendar, there is still a leap year almost every four years, but there is also a new rule. If the year ends in 00, it is only a leap year if the year’s number can be divided by 400. For this reason, 1800 and 1900 were not leap years, but 2000 was.

The new calendar was so accurate that over the next several hundred years, it was adopted by almost every country in the world. Over 400 years after its introduction, the Gregorian calendar is currently in use world-wide.


Some text and images adapted from :  www.nist.gov


1.Which early civilization had a month of 30 days?
a.The Babylonians  b.The Sumerians    c The Egyptians

2.Which early civilization also had a year with 365 days?
a.The Mayans  b.The Babylonians    c The Egyptians

3. Which is the name of the calendar currently most used around the world?
a. the Gregorian calendar   b. the Julian calendar  c. the Lunar calendar

4. How many days are there in a solar year?
a. 365      b. 365.25    c. 365.24219

5. When were leap years first used?
a. 46 BC     b. 1592     c. 1700

6. Which best describes the kind of calendar used today around the world?
a. a solar calendar, based on the revolution of the moon around Earth
b. a lunar calendar, based on the revolution of the moon around Earth
c. a solar calendar, based on the revolution of Earth around the sun

7. By our modern calendar, which of the following years WILL be a leap year?
a. 2100    b. 2500   c. 2800

8. Which of the following best describes the reason for creating leap years?
a. The Earth revolves around the sun.
b. The solar year does not divide into an even number of days, and it
would be difficult to add ¼ of a day onto each year.
c. Astronomers calculated the approximate length of a solar year.

9. Which statement best describes the problem with the Julian calendar?
a. Pope Gregory XIII did not like the Julian calendar.
b. The actual solar year was slightly shorter than the year calculated
for the Julian calendar, so there were too many leap years.
c. The actual solar year was slightly longer than the year calculated for
the Julian calendar, so there were not enough leap years.



2 comments:

  1. Could you document the orgin of the statement: " Ice-age hunters in Europe over 20,000 years ago scratched lines and gouged holes in sticks and bones, ..."? I have found this exact wording on more than 40 internet sites (I stopped counting), which verifies that multiple so called experts are taking the word of one person somewhere and in some time, but not giving credit. If no author can be identified, then sites should make this statement as THEORY. If 20,000 years ago, how exactly did that "someone" verify the information? How can so many publications propagate this statement so casually, as if it is bonified fact?

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  2. Thank you for the correction. Duly noted!

    ReplyDelete