When were you born and what day is it

anyway?

Calendars and Globalization

Problem:No year can be easily divided because the Earth’s

rotation around the sun is 365.2424 days (11 minutes less than 365 ¼ days)

Additionally the lunar cycle is 29 ½ days between each full moon (354 days if the year is divided into 12 months).

Any calendar trying to combine both movements is in trouble.

Chinese – counted years from the first Dyanasty

Roman – counted years from the foundation of the city

Ancient calendars:

Lunisolar It is based on exact astronomical

observations of the sun's longitude and the moon's phases. It attempts to have its years coincide with the tropical year and shares some similarities with the Jewish calendar. These similarities are that: an ordinary year has 12 months and a leap year has 13 months; and an ordinary year has 353-355 days while a leap year has 383-385 days.

Lunar (10 month cycle) March: named after Mars, the god of

war (first month of the New Year) April: from aperire, Latin for “to open”

(buds) May: named after Maia, the goddess of

growth of plants June: from junius, Latin for the goddess

Juno Qunitilis: Latin for “fifth” Sextilis: Latin for “sixth” September: from septem, Latin for

“seven” October: from octo, Latin for “eight” November: from novem, Latin for “nine” December: from decem, Latin for “ten”

Mayan 260 day, solar, and 584 day

Venus cycle

Julius Caesar“I came, I saw, I conquered, I named a month after myself (all hail Caesar!)Replaced the Roman calendar

(based on lunar cycles and a intercalary month) which was terribly seasonally inaccurate by 45 B.C.

Switched to a solar calendar with months of fixed lengths

Realigned the months with the seasons by adding 90 days in the “year of confusion” starting January 1, 46 B.C. (708 years after the foundation of Rome)

Each year was 365.25 days so: three years of 365 and one at 366 January, March, May, July, September, and

November were to have 31 days, and the other months 30, excepting February, which in common years should have only 29 days, but every fourth year 30 days – so the seasons would align with the sun.

Most months remained named as they had been, and as he was “living God” he named Quintilis (July) after himself (a nice time of year BUT beware the Ides of March!)

Caesar Augustus renamed Sextilis (August) after himself and extended it to 31 days to be equal to his uncle (stole a day from February)

Modified Julien Calendar January: named after Janus, the god of doors and gates February: named after Februalia, a time period when

sacrifices were made to atone for sins March: named after Mars, the god of war April: from aperire, Latin for “to open” (buds) May: named after Maia, the goddess of growth of plants June: from junius, Latin for the goddess Juno July: named after Julius Caesar in 44 B.C. August: named after Augustus Caesar in 8 B.C. September: from septem, Latin for “seven” October: from octo, Latin for “eight” November: from novem, Latin for “nine” December: from decem, Latin for “ten”

Further Modification and ErrorsThe calendar remained in effect throughout the

Roman Empire and the Church adopted it after Constantine declared Christianity the religion of the Empire.

Easter was placed on the first Sunday after the first full moon after the vernal (spring) equinox. If the equinox was wrong, then Easter was celebrated on

the wrong day and the placement of most of the other observances—such as the starts of Lent and Pentecost—would also be in error.

PROBLEM: The calendar was too long by 11 minutes and 14 seconds each year. The problem only grew worse with each passing year as

the equinox slipped backwards one full day on the calendar every 130 years.

Problems AriseAt the time of its introduction:

Julian calendar placed the equinox on March 25 By the Council of Nicea in 325, the equinox had fallen

back to March 21 – years began being dated from the birth of Christ (B.C. – before Christ, and A.D. – Anno Domini “the year of our Lord”)

By 1500, the equinox had shifted by 10 days.

A ten day difference was causing frustration for sailors, merchants, and farmers, whose livelihoods were timed to the seasons and the tides (lunar)

Additionally many medieval ecclesiastical records, financial transactions, and the counting of dates from the feast days of saints did not adhere to the standard Julian calendar because of local adjustments based on local pagan traditions.

The Church as our Salvation!As the only truly international organization in the

Middle Ages, and the importance of Easter’s celebration, the Catholic Church stepped in to clean up the mess. Problems:

1) Orthodox Church broke away in the Great Schism of 1054 A.D.

2) The Protestant Reformation lead to distrust of the Catholic Church (1517 A.D.)

3) Any place that did not use Christianity was using a different calendar all together. Pope Sixtus IV (r. 1471-1484) tried but nations fought him

and his chief astronomer was murdered. (pre-reformation) Pope St. Pius V (1568) made minor adjustments to match

the lunar calendar but Easter was still off.

Pope Gregory XIII (1582) Decided to fix everything all at once

rather than tinkering. The fix:

1. 10 days would be removed from the calendar. So October 4 was followed by October 15 in 1583.

2. The vernal equinox of 1583 and those that followed would occur around March 20, a date much closer to that of the Council of Nicaea.

3. To overcome the challenge of losing one day every 130 years, the new calendar omitted three leap years every 400 years, so that century years were leap years only when divisible by 400. (Using this method, 1600 and 2000 were leap years but 1700, 1800 and 1900 were not)

Problem: Technically, the pope

could not decree that nations and kingdoms adopt the new calendar, but its value was noted immediately in repairing centuries of inaccuracy on the part of the Julian calendar. Catholic countries adopted BUT no one else.

Gradual Globalization Protestant Germany adopted the calendar slowly. Prussia

accepted it in 1610, while the rest of the Protestant states decreed it only in 1700.

English, especially during the reign of Queen Elizabeth I (r. 1558-1603), rejected any thought of adopting a calendar created under the name of a pope and remained long suspicious that this was some Catholic plot. They were 10 days behind everyone else in Western Europe for

over 150 years. And after the leap year of 1700, they were 11 days behind.

The English compounded the dating dilemma further by celebrating New Year not on January 1 but according to the older custom of March 25.

American colonies adhered to the English system, they shared in the temporal displacement. Americans now celebrate the birth of George Washington on February 22, 1732, according to the Gregorian calendar. However, according to the English reckoning, he was born on February 11, 1731/32.

British Parliament passed the Calendar (New Style) Act in 1750. The New Year would begin on January 1 rather than March 25 and time would be counted according to the Gregorian calendar. The act went into effect on September 2, 1752, and the next day was decreed as September 14, 1782. (1/4 of the globe changed the calendar as a result)

Russia and the Eastern Orthodox Churches rejected the new calendar and continued to use the Julian calendar in their calculations for Easter. The Gregorian calendar was accepted as the civic calendar in

Russia only after the Russian Revolution in 1917. The Eastern Orthodox continue to use a revised Julian calendar,

with the exception of the Finnish Orthodox Church, which adopted the Gregorian calendar.

Colonialism spread the calendar globally except in China. Imperial China used its traditional calendar until 1917, The

Republic of China used a combined system, and Mao fully adopted the Gregorian calendar in 1949 with the Communist Revolution