One of the Mayan calendar's many cycles-one that lasted 5125 years-was the center of debate in 2012.
Thousands of people believed that once the cycle ended the world would, too.
See the Julian calendar The Julian calendar's predecessor, the Roman calendar, was a very complicated lunar calendar, based on the moon phases.
It required a group of people to decide when days should be added or removed in order to keep the calendar in sync with the astronomical seasons, marked by equinoxes and solstices.
The ancient Egyptians used a calendar similar to our current timekeeping system. Egyptologists believe the early Egyptians created the calendar more than 5,000 years ago and the calendar was eventually reformed; organizations and festival planners in Egypt continue to use it still today.
The Egyptians divided each month into 30 days; however, at the end of every year there existed five additional days.In order to create a more standardized calendar, Julius Caesar consulted an Alexandrian astronomer named Sosigenes and created a more regulated civil calendar, a solar calendar based entirely on Earth's revolutions around the Sun, also called a tropical year.It takes our planet on average, approximately 365 days, 5 hours, 48 minutes and 45 seconds (365.242189 days) to complete one full orbit around the Sun.The solution to this error was to replace the Julian calendar with the Gregorian calendar in 1582. Although the Gregorian calendar has become the international civil calendar, the Julian calendar was still used by some countries into the early 1900s.Some Orthodox churches still use it today to calculate the dates of moveable feasts, such as the Orthodox Church in Russia. This was determined because it is a time period long enough to include all of recorded history and includes some time in the future that would incorporate the three important calendrical cycles, the Golden Number Cycle, the Solar Cycle, and the Roman Indiction.The Athenians used the agricultural calendar to manage the seasons.This calendar provided significant aid during the farming season.The Julian calendar was used widely around the world until the Gregorian calendar was adopted.Its original purpose was to revise a calendar implemented by Julius Caesar.People lived their days using a calendar that most influenced their lives.Similar to other ancient calendars, the festival calendar included 12 months. Citizens used the democratic calendar to manage citizenship and the administration of the city.