A Brief History of the Modern Calendar

Accuracy of Gregorian Calendar

-Difference between calendar and solar year is only 26 seconds -Difference will increase by 0.53 seconds every 100 years due to the solar year gradually becoming shorter

Name the months in a Hebrew year

Tishri Heshvan Kislev Tebet Shebat Adar Nisan Lyar Sivan Tammuz Ab Elul (Veadar) Added 7 times ever 19 year period as an extra 20 day month (inserted between Adar and Nisan)

What does AD stand for?

anno Domini (in the year of the lord)

What does BC stand for?

Before Christ

What were the original 10 months of the Roman Calendar?

Martius, Aprilius, Maius, Junius, Quintilis, Sextilis, September, October, November, December

What are the 12 months in the Islamic Calendar

Muharram, Safar, Rabl I, Rabl II, Jumada I, Jumada II, Rajab, Shaban, Ramadan, Shawwal, Zulkadah, and Dhul-Hijja

What are the 12 animals in Chinese Calendar

Rat Ox Tiger Hare Dragon Snake Horse Sheep Monkey Rooster Dog Pig

What are movable feasts?

-Date vary from year to year as they are based of the phases of the moon -Ex: Ash Wednesday, Palm Sunday, and Easter

The Romans's Calendar

-Borrowed the earliest known calendar from the Greeks -Introduced by Romulus in the 700's BC and had 10 months and 304 days -Ignored 61 days which fell in the middle of winter

Hebrew Calendar

-Begins with an estimated moment of the world's creation -Placed this creation of the world 3,760 years and 3 months before the birth of Jesus Christ -Hebrew Year begins in September or October in the Gregorian Calendar -Based on the moon -Normally consists of 12 months

The World Calendar

-12 Months of 30 or 31 days -Year day at the end of the year -Leap-year day before July 1 every four years

What does BCE stand for?

-Alternate Gregorian numbering -Doesn't refer to Christ but instead refers to Before Common Era

What are immovable feasts?

-Based on the Solar Year (on a specific date every single year) -Christmas and the Nativity of the Blessed Virgin

Chinese Calendar

-Begins in 2637 BC -The year in which the Emperor Huangdi is said to have invented it -Counts in cycles of 60 years -The years in each cycle are further broken down into 12 years of cycles (5 of these in 1 larger cycle) -Each year corresponds with an animal -Based on the moon and generally is made up of 12 moons -Each month begins with a new moon (29 or 30 days) -Month is repeated seven times during each 19 year period -Year starts at the second new moon after the beginning of winter (Northern Hemisphere)

Islamic Calendar

-Begins with Muhammad's flight from Mecca to Medina -The flight is called the Hijra or Hejira (AD 622) -Based on the Moon -Has 12 months -Months are alternately 30 and 29 days long -Each year only has 354 days -Cycles of 30 years with 19 years with regular 354 days and 11 years with and extra day each -Islamic calendar nearly as accurate in measuring the lunar calendar as the Gregorian Calendar is in measuring the sun

What did the Roman Ruler Numa Pompilius do the the Roman Calendar?

-He added the months of January and February to the Calendary -This made the calendar 355 -Made the calendar almost corresponding to a lunar year -Extra month was also added every other year called Mercendinus (added 22 or 23 days to the year)

The Babylonians' Calendar

-Invented by the Babylonians who lived in Iraq -Added an extra month at odd intervals -Calendar with alternating 29 and 30 day months kept roughly in step with the lunar year -Added an extra month three times every eight years to keep up with the solar year -Great differences between the two caused the entire to become out of step until the Babylonians began to use a more reliable system in the 300's BC

Julian Calendar

-Months and seasons were out of sequence and were all wack by Caesar's time -48 BC Astronomer Sosignes suggested Julius to diregard the moon and divided the year into 12 months (31 and 30 days) except of February (29 days) - Every 4th year February gets an extra day (origins of the leap year) -Due to how wack the seasons were, that year there were 445 days in 46 BC -Called the year of Confusion -This calendar was used for more than 3,500 year and lasted 365 and 1/4 days -Actually about 11 minutes longer than the actual year -Gradual change but in AD 1580 spring equinox fell 10 days earlier than when it was stated to happen

The Fixed Calendar or Thirteen Month Calendar

-Months and years would begin on the same day of the week every year -All months would contain the same or nearly the same # of days - 13 months exactly 4 weeks long -Extra Month Sol would come before July -A year day would be placed at the end of the year (belongs to no week or month) -Every four years a leapyear day would be added just before July 1st

What months were renamed in the Julian Calendar?

-Quintilis was named July for Julius Ceasar -Sentilis was renamed August to honor Emperor Agustus

The Christian Church Calendar

-Regulated by both the sun and the moon

The Egyptians' Calendar

-The first to adopt a mainly solar calendar -Did this based of the Dog Star, Sirius -Came to recognize a year with 365 days made up of 12 months each with 30 days -Extra 5 days were also added to the end of the year -Didn't account for the pesky 1/4 of a day each year (results in being off by 1 day every 4 years_ -Earliest date on the Egyptian Calendar corresponds to the date 4236 BC (Gregorian Calendar

Gregorian Calendar

-Used by most people in the western world -Made by Pope Gregory XII -Has 12 months -11 months have 30 or 31 days -February has 29 days every leap year -Based on the year of Jesus Christ's birth -Corrected differences between the sun and calendar by dropping 10 days from October -Also that February would have an extra day in century years that could be evenly dived by 400

Calendar

A system of measuring and recording the passage of time -Based around the solar day in a solar year or lunar months -The creation of it was necessary due to seasons governing the lives of people, determining their needs, and controlled the supply of their natural food -The people needed to know when to prepare for the hardships of winter

What does CE stand for?

Alternate Gregorian numbering -States as common era