ASI W9700337r1.0

Moon Miners' Manifesto

#95 May 1996

Section the Artemis Data Book

The Moon Calendar Revisted


How Lunans will mark the days

by Peter Kokh
MMM #95 - May, 1996

Relevant Readings from Back Issues of MMM
MMM # 7 JUL '87, "Essays in 'M': Month, Meridian,
 Metonic Period"; "Moon Calendar"
MMM # 43 MAR '91, pp 4-6 "Dayspan"; "Nightspan";

In our attempt to uncover the early roots of a distinctively Lunan culture, we have looked at the Moon's "sixth-weight" gravity, its airlessness and exposure to the cosmic elements, the natural quarantine it imposes between scattered settlements, its dehydrated state, and its mixed bag of mineral assets. All of these will radically affect the development of Lunan civilization and culture from day one.

But there is yet another brute physical fact about the Moon that will affect everything just as deeply: the slow lethargic crawl of the Sun across the sky - the Moon's 14.75 day long "dayspans" and "nightspans", its 29.5 day "sunth".

[Astronomers call the period from full (or new) moon to full (or new ) moon a "lunation". From a lunar point of view, what is important is the sunrise to sunrise period. It would be silly for them to call it a "month". An "Earth" (full to full or new to new) would make sense only to Nearsiders. So we suggest the "sunth" as the logical term.]

While within habitats and biospheres lighting can be artificially controlled to reproduce the Earth-normal 24 hour lighting cycle, much of lunar industry will have to match the rhythm of its operations to that of the sunth. For even if we have nuclear power to sustain a higher level of nightspan industrial activity, the availability of abundant free solar power during dayspan, will mean that there will always be a premium on getting done as much energy-intensive work as possible during sun-up, preferentially leaving energy-light, labor-intensive tasks for nightspan - where possible. This mode of operations will create a strong fortnightly rhythm in many sectors of Lunan life. [see "Dayspan", Nightspan" ref. above.]

Pioneers will be free to use Earth's calendar, its days, dates, and months to govern their lives. Certainly Lunan astronomers and businessmen involved in export-import trade may need to do so. Those addicted to regular TV programs relayed live from Earth, and new settlers not yet committed to a lifetime stay may do the same. But for most Lunans, Earth's rhythms will be totally irrelevant. "The" thing that will matter above all is the timing of local sunrise and local sunset.

One way to harmonize the rhythms of their lives to those of the Moon would be to start with an all new Calendar, designed from scratch to better serve their purposes. If Lunans adopt a system of alternating 29 and 30 (24 hour) date sunths in which each sunth always begins on the same day of the week, then at each location on the Moon, sunrise and sunset would always fall on the same dates of the sunth. This would favor smooth production scheduling and a rhythm to count on.

The only way to do this, however, would be to insert an 8th day, 3 weeks out of eight, yielding 4 weeks exactly each sunth, alternately 29 and 30 dates long. There is a catch. This immediately uncouples Lunar weekday names from those in use on Earth. The eighth day could be inserted in a weekend, allowing for convenient holiday and festivity scheduling with no interruption to the work week, and should be a popular feature. But it is something sure to scare the pajamas off the various warring clans of Friday, Saturday, and Sunday fundamentalists, all of whom seem to think Earth's weekday sequence is an immutable, transcendental, cosmic law. Indeed, in the past, no proposal for calendar reform has been more certain to fail than a change in the Sunday-Saturday sequence.

For the sake of argument, let us assume that our pioneers are of the mind that this is a brand new world, and fresh beginnings are in order. They opt for the 24 hour date, the 7-8 day week, and the 4 week Sunth. The first of each calendar sunth would coincide with the "Full Earth" as seen from lunar Nearside (this occurs simultaneously with the "new moon" as seen from Earth). Nearsiders will have sunrise in the first half of the sunth, sunset in the second. Farsiders will have sunrise in the second half of the sunth, sunset in the first.

[A detail: because the sunth is 29.5306 days long, not 29.5 exactly, every 40th date, or on the closest weekend thereto, an extra hour would be added (as we do in the fall, switching back from daylight savings to standard time). This measure would keep the 29-30-29-30 pattern accurate - at the price of Earth dates lapping lunar dates by one every 2 1/2 years.]

Next, they will need new names for the days of the week, since their matchup with Earth's weekdays will always be ratcheting backwards with every 8th day insertion, 3 times every two sunths. Using the old names would mean utter confusion. Here are three name set suggestions:

(1) the names of the 7(8) biggest moons in the solar system: Luna, Io, Europa, Ganymede, Callisto, Titan, Triton, (Titania)

(2) the names of the 7(8) stars in the Big Dipper: Dubhe, Merak, Phad, Megrez, Alioth, Mizar, Alkaid, (Alcor). The problem with this suggestion is that the Big Dipper is not visible below latitude 30x south on the Moon and some southern settlements would thus find these names elitist.

(3) [this suggestion is the one this writer personally prefers] the names of the 7(8) stars of the Pleiades star cluster (and the attendants of Artemis, a Greek mythological moon goddess): Alcyone, Celaeno, Electra, Maia, Merope, Sterope, Taygeta, (Pleione and/or Atlas, the parents of the seven sisters). Pleione could be used for the 8th day inserted in the mid-sunth weekend, Atlas for the 8th day inserted in every other sunth-end weekend. The Pleiades can be seen from all locations on the Moon as they cross the sky above the lunar equator. The 7-8 date week, again to avoid confusion with the invariable 7 day period of Earth, could be called the Pleiad.

Time zones?

On the Moon, the Sun rises an hour earlier every 9.5 miles you travel to the east, and that's at the equator, in a shorter distance closer to the poles. There is a 24 hour difference every 12.2x or every 230 miles along the equator. It will be much simpler for all the Moon to have just one time zone.

The fun has just begun. The Sunth-Pleiad solution is the easy part. Those of you figuring ahead must have realized that 12 sunths = 354+ days, 11 less than an Earth standard year.

This has always been the problem with counting by moons, instead of idealized 30-31 day calendar months. On Earth, while the period between full moons or new moons is a handy yardstick, the one thing that really matters above all is the succession of seasons in a 365 day cadence. It is the Solar year, not the lunar year that is king. Two cultural traditions, Jewish and Islamic, have adopted lunar calendars nonetheless.

The Jewish calendar attempts to keep step with the solar year by adding a thirteenth intercalary month, seven years out of nineteen. [There are 235 lunar months exactly in 19 calendar years of 228 calendar months. This is called the Metonic Period.] The Moslems make no attempt to keep pace and end up counting 33 of their years to every 32 of ours (the time it takes the faster 354 day year to lap the slower 365 day).

On the Moon, Earth's seasons by which weather governs agriculture, are of no real concern. Lunar agriculture, in controlled biospheres, can set its own seasons, and will be more sensitive to the availability of free sunlight on a sunthly schedule of two weeks on, two weeks off. Nonetheless, there will be incentives to keep the lunar sunth year and terrestrial solar years in step, at least over the long haul. The Moon, unlike Mars, is in Earth's backyard, and the sheer volume of live communications, and the heavy regular traffic in exports and imports make Earth's dominant calendar something not to ignore lightly.

This said, are there any solutions better than the two mentioned above? The problem with the Jewish solution of twelve 354 day years of 12 lunar months interspersed with seven 383-4 day years of 13 lunar months is that the years are very unequal, a severe handicap for fiscal accounting and economic management. The Islamic solution is to ignore the problem and not make any attempt at concordance.

Option A

One possible but radical synthesis is a Metonic Period sequence of 19 years of 12 lunar months (sunths) of 354 days each, followed by a once-a-generation cultural, social, and institutional renaissance period of 7 "catch up" lunar months (sunths), at the end of which, the lunar and Earth calendars would again be in step. This would provide equal years for accounting purposes, and the cultural, social, artistic, institutional renewal once a generation would be planned, anticipated, and provide a culturally treasured shot-in-the-arm. There are problems with this: how do you count anniversaries, especially for events taking place in the 7 renaissance sunths?

Option B

Perhaps an even more radical solution is to decouple the sunth-sequence from the year. We already have a calendar in which the weekdays are decoupled from the days of the month. That is, January 1st can fall on any day of the week. Months begin in midweek (Mon. thru Sat.) six times out of seven. We could have a sequence of 235 sunths (repeating every 19 years) and allow the Calendar Year or New Years Day to float through the sunths, much as we allow the "First" to float through the week. The sunths could simply be numbered 1 through 235 instead of named. Or, easier to sell, there could be a sequence of 12 names with a thirteenth intercalary sunth 7 years out of 19, Jewish style. A floating New Years Day would keep the terrestrial year counting cadence, while still coupling lunar life to the dayspan-nightspan pace of the sunth.

One could hardly fault Jews for suggesting the wholesale adoption of their lunar calendar complete with the names they have used for the lunar months for thousands of years. For a probably pluralist lunar society, this may not be a diplomatic solution. New neutral sunth names may be in order. Might we suggest something simple: (u in sun is unaccented)

Firstsun, Secondsun, Thirdsun, Fourthsun, Fifthsun, Sixthsun, Seventhsun, Eighthsun, Ninthsun, Tenthsun, Eleventhsun, Twelvethsun, (Leapsun)

Firstsun would begin with the last (if there are two) new moon (full Earth) in December. In case of two new moons (full Earths), the first would mark the beginning of Leapsun. In either case New years Day, January 1st on Earth, would fall somewhere between Firstsun 1 and Firstsun 29 on the Moon.

Option C

Yet another possible solution would be to have 12 sunths plus 11 extra year end reset days so that all sunths of any given year would have the having the same date/day sunrise-sunset pattern, which would be different from year to year in a pattern cycle that repeats every 19 years (the Metonic Period again). This solution would allow a set conversion to terrestrial dates and allow easy tracking of anniversaries. Because each of the 19 years of the sequence would have a characteristic pattern, they might be named, much as in the totemic Chinese system (year of the dog, of the pig, etc.).

There are two additional benefit of this system: the introduction of variety (the same variety we experience by important dates falling on different days of the week, year after year); and "fairness", if you will. By options A and B, some settlements would always experience sunrise and sunset on their weekends, (some on 3 day weekends!) others somewhere during the week. As industrial operations have to shift gear at these two times, the timing will come with different inconveniences during weekends than during the week.

The Lunan settlers themselves must consider the merits of the various proposals above and choose one, or come up with something different. Please feel free to "vote" for the solution you like best, or to propose another.

Whatever calendar arrangement settlers eventually choose, it is sure to reverberate throughout Lunan culture, adding yet another layer of distinctive and characteristic difference from the variegated "family" of cultures on Earth.

Physical Calendars

Lunar calendars need to be "perpetual" or recyclable. Options A and B allow a simple two sunth calendar (the 29, 30 date rotation) to be used indefinitely. A movable accent bar over a list of sunths on the side or above would be all that was needed to make it complete. If the day / date squares were reversible tiles, one side the photo-negative of the other, then each calendar could be customized easily to the local sunrise / sunset (dayspan / nightspan) pattern. Materials available are glass, ceramic, and metal. Recyclable organic art du jour could take the place of the "scene of the month" on our own paper calendars. It will be interesting.


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