Tranquility Calendar

After the Earth was evacuated in the afermath of the Nanodisaster, most refugees adopted the Lunar Calendar, also known as the Tranquility Calendar, which was already widely used in the colonies of the Solar System. For some centuries after the Great Expulsion many refugees continued to use the old months while adopting the new yearly dates; but by the time of the First Federation the new Lunar Months has also been widely adopted. Today most timekeeping software is capable of displaying the date according to the After Tranquility system; because of relativistic effects (discussed here) this date can generally only be regarded as approximate. The Standard Year in the Tranquility Calendar is the same as that for Old Earth, and has also been adopted as a standard measurement throughout the Terragen Sphere.

The Tranquility Calendar

The Tranquility Calendar is a calendar that had its roots in science. Its center date in history is called Moon Landing Day. According to tradition, the actual center point in time was the exact moment the word 'tranquility' was mentioned in the famous quote - Houston, Tranquility Base Here. The Eagle Has Landed. These were the first words ever spoken by a human from the surface of another world. Moon Landing Day was not counted as part of any month or year; it had 20 hours, 18 minutes, and 1.2 seconds Before Tranquility (B.T.), and 3 hours, 41 minutes, and 58.8 seconds After Tranquility (A.T). The Gregorian equivalent of Moon Landing Day was July 20, 1969 c.e..

The Tranquility Calendar is logically structured so that days of the week do not vary from month to month, and there are no changes in calendar structure based on year.

The names of the months

Because the Tranquility calendar was designed as a calendar for science, the 13 months were named after scientists. The thirteen individuals who are commemorated by the calendar were all (of course) born on Earth, and despite the large amount of historical data which was lost during the Nanoswarms, much information is preserved on Luna about almost all of them

The Thirteen Months In order

Archimedes	Brahe	Copernicus	Darwin	Einstein	Faraday	Galileo
Hippocrates	Imhotep	Jung	Kepler	Lavoisier	Mendel

Archimedes (circa 287 to 212 B.C.), Greek mathematician and inventor; Tycho Brahe (1546 to 1601), Danish astronomer; Nicolaus Copernicus (1473 to 1543), Polish astronomer; Charles Darwin (1809 to 1882), English naturalist; Albert Einstein (1879 to 1955), American (German-born) theoretical physicist; Michael Faraday (1791 to 1867), English chemist and physicist; Galileo Galilei (1564 to 1642), Italian astronomer and physicist; Hippocrates (circa 460 to circa 377 B.C.), Greek physician; Imhotep (circa 2980 to 2950 B.C.), Egyptian physician and sage; Carl Jung (1876 to 1961), Swiss psychologist and psychiatrist; Johannes Kepler (1571 to 1630), German astronomer; Antoine Lavoisier (1743 to 1794), French chemist; Gregor Mendel (1822 to 1884), Austrian botanist. (Historical Note; little reliable information survives about Hippocrates or Imhotep, even on Luna).

To facilitate record keeping, the months proceed in alphabetical order. The first day of each year is the first day of Archimedes (July 21 on the Gregorian calendar). The last day of each Tranquility year is called Armstrong Day. Named for the first human to step on the moon, Armstrong Day celebrates the anniversary of Moon Landing Day. Thus July 20, 1970 c.e., was the Gregorian equivalent of Armstrong Day, 1 A.T., and July 20, 1989 c.e., was Armstrong Day, 20 A.T.

The days of the week

Friday

Saturday

Sunday

Monday

Tuesday

Wednesday

Thursday

Each month has exactly 28 days. The first of each month is always a Friday. The twenty-eighth of each month is always a Thursday. There are 365 days in each year, except for leap years, in which there are 366 days.

Thirteen month of 28 days each totals 364 days. Each year on the anniversary of Moon Landing Day there is a special day of the year called Armstrong Day. This day has no day of the week. It falls between Mendel 28 and Archimedes 1 of the following year.

Finally, the Tranquility calendar equivalent of leap day is called Aldrin Day. This day also has no day of the week. Named for Armstrong's fellow moon walker, Aldrin Day occurs every four years, with some exceptions. The exceptions are the leap days in every 400 years that are dropped to keep the calendar astronomically precise. Aldrin Day falls between the twenty-seventh and twenty-eighth of Hippocrates (February 29).

How does the Tranquility Calendar map to the Gregorian?

Jan 1
Far 25
M

Jan 2
Far 26
T

Jan 3
Far 27
W

Jan 4
Far 28
TH

Jan 5
Gal 1
F

Jan 6
Gal 2
S

Jan 7
Gal 3
S

Jan 8
Gal 4
M

Jan 9
Gal 5
T

Jan 10 Gal 6
W

Jan 11
Gal 7
TH

Jan 12 Gal 8
F

Jan 13 Gal 9
S

Jan 14
Gal 10
S

Jan 15 Gal 11

Jan 16 Gal 12

Jan 17 Gal 13

Jan 18 Gal 14

Jan 19 Gal 15

Jan 20
Gal 16

Jan 21 Gal 17

Jan 22 Gal 18

Jan 23 Gal 19

Jan 24 Gal 20

Jan 25 Gal 21

Jan 26 Gal 22

Jan 27 Gal 23

Jan 28
Gal 24

Jan 29 Gal 25

Jan 30 Gal 26

Jan 31 Gal 27

Feb 1
Gal 28

Feb 2
Hip 1

Feb 3
Hip 2

Feb 4
Hip 3

Feb 5
Hip 4

Feb 6
Hip 5

Feb 7
Hip 6

Feb 8
Hip 7

Feb 9
Hip 8

Feb 10 Hip 9

Feb 11
Hip 10

Feb 12
Hip 11

Feb 13 Hip 12

Feb 14
Hip 13

Feb 15 Hip 14

Feb 16 Hip 15

Feb 17
Hip 16

Feb 18 Hip 17

Feb 19 Hip 18

Feb 20 Hip 19

Feb 21
Hip 20

Feb 22 Hip 21

Feb 23 Hip 22

Feb 24 Hip 23

Feb 25
Hip 24

Feb 26
Hip 25

Feb 27 Hip 26

Feb 28
Hip 27

Feb 29
Aldrin Day

Mar 1
Hip 28

Mar 2
Imh 1

Mar 3 Imh 2

Mar 4 Imh 3

Mar 5 Imh 4

Mar 6 Imh 5

Mar 7 Imh 6

Mar 8 Imh 7

Mar 9
Imh 8

Mar 10 Imh 9

Mar 11 Imh 10

Mar 12 Imh 11

Mar 13 Imh 12

Mar 14 Imh 13

Mar 15 Imh 14

Mar 16
Imh 15

Mar 17
Imh 16

Mar 18 Imh 17

Mar 19
Imh 18

Mar 20 Imh 19

Mar 21 Imh 20

Mar 22 Imh 21

Mar 23 Imh 22

Mar 24 Imh 23

Mar 25 Imh 24

Mar 26 Imh 25

Mar 27 Imh 26

Mar 28 Imh 27

Mar 29 Imh 28

Mar 30
Jng 1

Mar 31 Jng 2

Apr 1 Jng 3

Apr 2 Jng 4

Apr 3 Jng 5

Apr 4 Jng 6

Apr 5 Jng 7

Apr 6 Jng 8

Apr 7
Jng 9

Apr 8 Jng 10

Apr 9 Jng 11

Apr 10 Jng 12

Apr 11 Jng 13

Apr 12 Jng 14

Apr 13
Jng 15

Apr 14 Jng 16

Apr 15 Jng 17

Apr 16 Jng 18

Apr 17 Jng 19

Apr 18 Jng 20

Apr 19 Jng 21

Apr 20 Jng 22

Apr 21
Jng 23

Apr 22
Jng 24
S

Apr 23 Jng 25
M

Apr 24 Jng 26
T

Apr 25 Jng 27
W

Apr 26 Jng 28
TH

Apr 27
Kep 1
F

Apr 28 Kep 2
S

Apr 29 Kep 3
S

Apr 30
Kep 4
M

May 1 Kep 5
T

May 2 Kep 6
W

May 3 Kep 7
TH

May 4 Kep 8
F

May 5 Kep 9
S

May 6
Kep 10

May 7
Kep 11

May 8
Kep 12

May 9
Kep 13

May10
Kep 14

May 11
Kep 15

May 12
Kep 16

May 13
Kep 17

May 14
Kep 18

May 15
Kep 19

May16
Kep 20

May 17 Kep 21

May 18 Kep 22

May 19 Kep 23

May 20
Kep 24

May 21
Kep 25

May 22 Kep 26

May 23 Kep 27

May 24 Kep 28

May 25
Lav 1

May 26
Lav 2

May 27
Lav 3

May 28
Lav 4

May 29
Lav 5

May 30
Lav 6

May 31
Lav 7

Jun 1
Lav 8

Jun 2
Lav 9

Jun 3 Lav 10

Jun 4
Lav 11

Jun 5
Lav 12

Jun 6
Lav 13

Jun 7 Lav 14

Jun 8
Lav 15

Jun 9
Lav 16

Jun 10 Lav 17

Jun 11 Lav 18

Jun 12 Lav 19

Jun 13 Lav 20

Jun 14 Lav 21

Jun 15
Lav 22

Jun 16
Lav 23

Jun 17
Lav 24

Jun 18
Lav 25

Jun 19
Lav 26

Jun 20
Lav 27

Jun 21
Lav 2

Jun 22
Men 1

Jun 23
Men 2

Jun 24
Men 3

Jun 25
Men 4

Jun 26
Men 5

Jun 27
Men 6

Jun 28
Men 7

Jun 29
Men 8

Jun 30
Men 9

Jul 1
Men 10

Jul 2
Men 11

Jul 3
Men 12

Jul 4
Men 13

Jul 5
Men 14

Jul 6
Men 15

Jul 7 Men 16

Jul 8 Men 17

Jul 9 Men 18

Jul 10
Men 19

Jul 11
Men 20

Jul 12 Men 21

Jul 13
Men 22

Jul 14
Men 23

Jul 15
Men 24

Jul 16
Men 25

Jul 17 Men 26

Jul 18 Men 27

Jul 19
Men 28

Jul 20
Armstrong
Day

Jul 21
Arc 1

Jul 22
Arc 2

Jul 23 Arc 3

Jul 24
Arc 4

Jul 25 Arc 5

Jul 26
Arc 6

Jul 27 Arc 7

Jul 28
Arc 8

Jul 29
Arc 9

Jul 30
Arc 10

Jul 31
Arc 11

Aug 1
Arc 12

Aug 2 Arc 13

Aug 3
Arc 14

Aug 4 Arc 15

Aug 5 Arc 16

Aug 6 Arc 17

Aug 7 Arc 18

Aug 8 Arc 19

Aug 9 Arc 20

Aug 10 Arc 21

Aug 11 Arc 22

Aug 12
Arc 23

Aug 13
Arc 24

Aug 14 Arc 25

Aug 15 Arc 26

Aug 16 Arc 27

Aug 17
Arc 28

Aug 18
Bra 1

Aug 19
Bra 2

Aug 20
Bra 3

Aug 21
Bra 4

Aug 22
Bra 5

Aug 23
Bra 6

Aug 24 Bra 7

Aug 25 Bra 8

Aug 26
Bra 9

Aug 27 Bra 10

Aug 28 Bra 11

Aug 29 Bra 12

Aug 30
Bra 13

Aug 31
Bra 14

Sep 1
Bra 15

Sep 2
Bra 16

Sep 3
Bra 17

Sep 4
Bra 18

Sep 5
Bra 19

Sep 6
Bra 20

Sep 7
Bra 21

Sep 8
Bra 22

Sep 9
Bra 23

Sep 10
Bra 24

Sep 11
Bra 25

Sep 12 Bra 26

Sep 13 Bra 27

Sep 14
Bra 28

Sep 15 Cop 1

Sep 16 Cop 2

Sep 17 Cop 3

Sep 18 Cop 4

Sep 19
Cop 5

Sep 20 Cop 6

Sep 21 Cop 7

Sep 22 Cop 8

Sep 23
Cop 9

Sep 24 Cop 10

Sep 25 Cop 11

Sep 26 Cop 12

Sep 27 Cop 13

Sep 28
Cop 14

Sep 29
Cop 15

Sep 30 Cop 16

Oct 1 Cop 17

Oct 2 Cop 18

Oct 3 Cop 19

Oct 4 Cop 20

Oct 5 Cop 21

Oct 6
Cop 22

Oct 7 Cop 23

Oct 8 Cop 24

Oct 9 Cop 25

Oct 10 Cop 26

Oct 11 Cop 27

Oct 12
Cop 28

Oct 13 Dar 1

Oct 14 Dar 2

Oct 15 Dar 3

Oct 16 Dar 4

Oct 17 Dar 5

Oct 18 Dar 6

Oct 19 Dar 7

Oct 20
Dar 8

Oct 21
Dar 9

Oct 22 Dar 10

Oct 23 Dar 11

Oct 24
Dar 12

Oct 25 Dar 13

Oct 26
Dar 14

Oct 27
Dar 15

Oct 28 Dar 16

Oct 29
Dar 17

Oct 30 Dar 18

Oct 31 Dar 19

Nov 1
Dar 20

Nov 2 Dar 21

Nov 3
Dar 22

Nov 4
Dar 23

Nov 5 Dar 24

Nov 6 Dar 25

Nov 7 Dar 26

Nov 8 Dar 27

Nov 9
Dar 28

Nov 10
Ein 1

Nov 11
Ein 2

Nov 12
Ein 3