The Tranquility calendar

Calendar

A calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...

is a solar calendar

Solar calendar

A solar calendar is a calendar whose dates indicate the position of the earth on its revolution around the sun .-Tropical solar calendars:...

 proposal for calendar reform

Calendar reform

A calendar reform is any significant revision of a calendar system. The term sometimes is used instead for a proposal to switch to a different calendar.Most calendars have several rules which could be altered by reform:...

 designed by Jeff Siggins providing for a year of 13 months of 28 days each, with one day at the end of each year belonging to no month or week, and a leap day approximately every 4 years.

Rules

The calendar's center date in history is called Moon Landing Day. The actual center point in time is the exact moment the word tranquility is mentioned in this somewhat famous quote - Houston, Tranquility Base

Tranquility Base

Tranquility Base was the name given by American astronaut Neil Armstrong to the landing site on the moon where the Apollo 11 Lunar Module Eagle made the first moon landing....

 Here. The Eagle Has Landed. Moon Landing Day has 20 hours, 18 minutes, and 1.2 seconds Before Tranquility and 3 hours, 41 minutes, 58.8 seconds After Tranquility.

The calendar year has 13 months each with 28 days (divided in exactly 4 weeks) plus an extra day at the end of the year not belonging to any month (and so 365 days).

The months are named after famous scientists: Archimedes

Archimedes

Archimedes of Syracuse was a Greek mathematician, physicist, engineer, inventor, and astronomer. Although few details of his life are known, he is regarded as one of the leading scientists in classical antiquity. Among his advances in physics are the foundations of hydrostatics, statics and an...

, Brahe

Brahe

Brahe is the name of a Scanian noble family that was influential in both Danish and Swedish history but has its family roots in Swedish origin. The first member of the family is speculated to have been Verner Braghde from Halland. Better documented is Peder Axelsen Brahe who appears in late 14th...

, Copernicus, Darwin

Charles Darwin

Charles Robert Darwin FRS was an English naturalist. He established that all species of life have descended over time from common ancestry, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.He published his theory...

, Einstein, Faraday

Michael Faraday

Michael Faraday, FRS was an English chemist and physicist who contributed to the fields of electromagnetism and electrochemistry....

, Galileo, Hippocrates

Hippocrates

Hippocrates of Cos or Hippokrates of Kos was an ancient Greek physician of the Age of Pericles , and is considered one of the most outstanding figures in the history of medicine...

, Imhotep

Imhotep

Imhotep , fl. 27th century BC was an Egyptian polymath, who served under the Third Dynasty king Djoser as chancellor to the pharaoh and high priest of the sun god Ra at Heliopolis...

, Jung

Jung

Carl Jung was a Swiss psychiatrist, an influential thinker and the founder of analytical psychology.Jung may also refer to:* Jung * JUNG, Java Universal Network/Graph Framework-See also:...

, Kepler, Lavoisier, and Mendel

Gregor Mendel

Gregor Johann Mendel was an Austrian scientist and Augustinian friar who gained posthumous fame as the founder of the new science of genetics. Mendel demonstrated that the inheritance of certain traits in pea plants follows particular patterns, now referred to as the laws of Mendelian inheritance...

. The 365th day is called Armstrong

Neil Armstrong

Neil Alden Armstrong is an American former astronaut, test pilot, aerospace engineer, university professor, United States Naval Aviator, and the first person to set foot upon the Moon....

 Day; the leap day is called Aldrin

Aldrin

Aldrin is an organochlorine insecticide that was widely used until the 1970s, when it was banned in most countries. It is a colourless solid. Before the ban, it was heavily used as a pesticide to treat seed and soil...

 Day.

Days that do not belong to a month are deemed to be outside the week and always occur between a day deemed Thursday and a day deemed to be Friday.

The first day of each year, Archimedes 1, is deemed a Friday and every subsequent day that belongs to a month is deemed to be in the conventional 7-day week.

The year starting the day after Moon Landing Day, and lasting until Armstrong Day, is designated 1 After Tranquility, or 1 AT, with subsequent years numbered in order; the year lasting from July 2011 until July 2012 is 43 AT. The year ending the day before Moon Landing Day, and starting on the previous Armstrong Day, is 1 Before Tranquility, or 1 BT.

While Moon Landing Day's definition roughly correlates the calendar to Greenwich Mean Time

Greenwich Mean Time

Greenwich Mean Time is a term originally referring to mean solar time at the Royal Observatory in Greenwich, London. It is arguably the same as Coordinated Universal Time and when this is viewed as a time zone the name Greenwich Mean Time is especially used by bodies connected with the United...

, as there are no leap seconds, it more closely approximates TAI

International Atomic Time

International Atomic Time is a high-precision atomic coordinate time standard based on the notional passage of proper time on Earth's geoid...

 than UTC.

The leap year

Leap year

A leap year is a year containing one extra day in order to keep the calendar year synchronized with the astronomical or seasonal year...

 system matches the Gregorian Calendar

Gregorian calendar

The Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...

; thus, the 400-year cycle of leap years starts on 31 AT - every four years is a leap year, except for every hundredth year which is not, except for every four hundredth year which is.

Because each month consists of exactly four weeks, the first day of each month and every seventh day after that for the rest of the month is deemed to be a Friday, the second day of each month and every seventh day after that for the rest of the month is deemed to be a Saturday, and so on. Therefore, each month begins on a Friday and ends on a Thursday.

This causes all months to look like this:

Fri	Sat	Sun	Mon	Tue	Wed	Thu
1	2	3	4	5	6	7
8	9	10	11	12	13	14
15	16	17	18	19	20	21
22	23	24	25	26	27	28

The 13 months and extra days occur on the following Gregorian dates:

Month	Starts	Ends
Archimedes	July 21	August 17
Brahe	August 18	September 14
Copernicus	September 15	October 12
Darwin	October 13	November 9
Einstein	November 10	December 7
Faraday	December 8	January 4
Galileo	January 5	February 1
Hippocrates	February 2	March 1
Aldrin Day	February 29
Imhotep	March 2	March 29
Jung	March 30	April 26
Kepler	April 27	May 24
Lavoisier	May 25	June 21
Mendel	June 22	July 19
Armstrong Day	July 20

History

The Tranquility Calendar is similar to the International Fixed Calendar

International Fixed Calendar

The International Fixed calendar is a solar calendar proposal for calendar reform designed by Moses B...

 as well as the earlier Positivist Calendar

Positivist calendar

The positivist calendar was a calendar reform proposal by Auguste Comte in 1849. After revising the earlier work of Marco Mastrofini, Comte's proposed calendar was a solar calendar which had 13 months of 28 days, and an additional festival day commemorating the dead, totalling 365 days.This extra...

 published in 1849 by French philosopher Auguste Comte

Auguste Comte

Isidore Auguste Marie François Xavier Comte , better known as Auguste Comte , was a French philosopher, a founder of the discipline of sociology and of the doctrine of positivism...

(1798–1857). Comte based his calendar on Polynesian calendars.

Advantages

Several advantages do exist on this calendar, mainly related to its organization. When compared to the Gregorian, it is clear that this calendar is much simpler and pratical:

• every year has exactly 52 weeks divided in 13 months;
• each month has exactly 28 days divided in 4 weeks;
• every month/year's day has the same week day (i.e. n'th month/year day is always the m'th week's day, where m is the remainder of n/7).

When compared to other proposals, this calendar keeps the same days per year, and the same days per week, which are two advantages that ease possible change.

On this proposal, the number of national holidays that do not fall on weekends are no longer year dependent. This no longer causes certain years to have more workdays than others.

Disadvantages

Thirteen, being prime, is not evenly divisible, putting all activities currently done on a quarterly basis out of alignment with the months.

Several religious groups oppose any interruption of the seven-weekday sequence.

External links

• http://www.mithrandir.com/Tranquility/tranquility.html
• Orion's Arm used in a published fictional setting