A calendar serves many purposes. People would not forget birthdays, anniversaries, miss appointments and never know what day it is. The oldest calendar may be 30,000 years old. In present time, most of the countries in the world are using the Gregorian calendar.

The Gregorian calendar differs from the solar year by 26 seconds per year. It gains three days in every 10,000 years. It was named after Pope Gregory XIII who is credited with introducing it. It was adopted initially in 1582 by several Roman Catholic countries in Europe and spread to most parts of the world very gradually thereafter.


Fast Facts: –

  • The term has been derived from the Latin word Kalendae that means the first day of a month.
  • The Mayan system dates back to at least the 5th century BCE, and by 900 AD had been refined into a complex one, but it was more accurate.
  • The last country to adopt the diabolical calendar was Greece in 1923.
  • The Chinese people have their own calendar that they use for defining the occurrences of festivals. It is closely related to astrology.
  • The years in the Chinese system are named after Zodiac animals.
  • The current system requires a leap day, February 29, to be added every four years so that it can match up with the tropical year.
  • In ancient times, a month was calculated roughly by the length of time it takes the Moon to orbit Earth and begin a new phase.
  • The earliest record of a seven-day week dates back to 600 BCE ancient Babylon, where a holy day was celebrated every seven days starting with a new moon.
  • The origin of the Julian calendar dates back to 46 B.C.
  • Before the adoption of the Gregorian system, the English New Year began on March 25, Lady Day.
  • Today most people use their phones – laptops or PC calendar.