Weights and Measures
The history of measurement standardization is fraught with economic and political tension. It’s notable that throughout known Terran history the way humans measure quantities like distance, time, mass, volume, etc., changed markedly around radically new socioeconomic orders. For the facilitation of fair trade—and the taxation of that trade—governments, corporations, and individuals alike need to be on the same page. Rule of law and the very principle of equity otherwise collapses. If a seller hasn't labeled their goods with customary units, caveat emptor.
But regionally, it might be convenient or even necessary to create new and novel abstractions. For instance, inhabited planets do not all rotate at the same rate. Gravity is not the same everywhere. And various trades such as medicine may have a legacy history of research in a set of metrics that are not optimal but must be understood by its scholars.
Despite centuries or millennia of clever new weights and measures better suited to their particular environment, the Barystates all retained a complete record of Old World Terran measurement systems. These include the base 10 metric system and the definition of the (kilo)gram and the second. Seizing on this shared knowledge, and for the sake of communication and commerce, the Barystates came together to standardize its renewed use. Distance, mass, volume, etc. are all carried over from ancient documentation.
The Terran timekeeping system is also largely intact with a few truncations: there are no leap years, leap seconds, or variable days in a month. Changes to the time system of old were made both for simplicity and as a compromise. Every Barystate was able to keep some temporal metric it found most useful. For example, a Maridean day is exactly 24 hours and a Sibylean orbit around Astrild is 60 of its gyres around Dowager, corresponding to 360 of these Terran and Maridean-like days, adding up to what became a standardized year.
The year was set to 1 upon the signing of the accords at the tediously named International Congress on Trade, Immigration, and Metrics. The novel Stardust takes place in 87 CY (Congressional Year 87).
There still exist several eccentricities in weights and measures at the regional level, particularly in timekeeping:
In the Novani Republic
Maridean brights are the standardized day throughout The Bary, 24 hours long. However, the words “bright” and “day” are used interchangeably within the Republic and some parts beyond to simply refer to the cycle of the human circadian rhythm.
In the Sibylean Kingdom
In the Kingdom, a gyre is the sidereal revolution of Sibyl around Dowager. One revolution of Dowager around Astrild in turn is almost precisely a standard year, and takes 60 gyre.
A rayspan is a Sibylean word for a day. If Sibyl were much closer to Dowager, it would certainly be tidally locked. There is evidence this may occur in the far future, however the world’s mass and momentum are currently sufficient to ensure it will not meet Sebek’s fate. A Sibylean rayspan is approximately 36 hours and one-quarter of a gyre. The astronomical twilight hours on Sibyl are particularly long. The Sibyleans call the shining of Astrild upon their home raytime.
In the Geminese Dominion
In addition to using international standard time, the Lucian religion counts its religious years by the solar cycles of Lux. Specifying the beginning of a new cycle is a joint effort between the Lucian hierophant and astrophysicists, who closely monitor Lux. Days are separate for Castor and Pollux, which are always specified with a local reference for rotation, such as: the 420th Prime Polluci, Cycle 155.
In the Feronian League
There are many multiple states in the Saffron system and a full accounting of the temporal eccentricities of each culture’s history would be beyond the scope of this article. In recent years the Feronians have more fully embraced international conventions in timekeeping.
In the Empyrean Commonwealth
Before it signed the international metrics accords, the Commonwealth used metric seconds to record the passage of time. Evidence of this will be clear to any visitor wandering the blue-collar or underclass streets of Commonwealth space colonies. A kilosecond is 16.7 minutes, a megasecond is 11.6 standard days, and so on.