o yis Istran calendar: date and time
The Kaliedan orbit lasts for 380.401 days. In line with other Societies, the Istran Calendar (ic) starts its year at the northern hemisphere's spring equinox. The Istran count of years starts with the (alleged) arrival of the Starman on the planet some 4 millennia ago. The Grand Treaty orbit gt1200 corresponds to the Istran Calendar orbit ic4121.
The Istran calendar divides the orbit into 12 months, the first 11 of which have 32 days (64 half-days) while the last month of the year has 28 days (54 half-days). The result of this division is that after ten orbits the new year begins four days befor the spring equinox; to fix this discrepancy four leap days (8 half-days) are added to the last month every tenth orbit. An additional day is supposed to be added to the end of every 1,000th orbit, though this has not apparently happened on a routine basis: by agreement across all the Istran lands and isles the millennial orbit ic4000 was extended by an additional 3 days (to give an orbit of 387 days) to ensure orbit ic4001 commenced on the equinox.
Naming the months in O Yis
The names of the months are in fact descriptive phrases which are routinely shortened into single words. Month names are treated as common nouns by O Yis speakers, not proper nouns.
| Month after spring equinox | Short form name | Long form name | Translation |
|---|---|---|---|
| First month | o/do hvedirhemjor | an jorre m'o rede hvedirhem dzi | the time of preparations |
| Second month | o/do tynnehemjor | an jorre m'o tynnehem rette | the time for sowing |
| Third month | o/xo redemclépjor | an jorre om rede demclép | the time of much daylight |
| Fourth month | y/urt zahemjor | an jorre m'y rede zahem dzi | the time of calm weather |
| Fifth month | an/a xémjacjor | an jorre ac xémjac | the time of warmth |
| Sixth month | ni/niab bauqveitibjor | ni baustib bym qveit | the harvest from the land |
| Seventh month | e/dzeg tzakkorjor | an jorre m'e rede tzakkor dzi | the time for storms |
| Eighth month | o/do hlembyrhemjor | an jorre m'o hlembyrhem rette | the time for ploughing |
| Ninth month | o/xo jademclépjor | an jorre om jan demclép | the time of little daylight |
| Tenth month | an/a tzúfojacjor | an jorre ac tzúfojac | the time of coolness |
| Eleventh month | ni/niab bauzaurzibjor | ni baustib um zaurz | the harvest from the sea |
| Twelfth month | an/a xollitjacjor | an xollitjac om tavver | the end of the year |
Month names are seasonal in nature, referring either to a typical activity that takes place at that time of the orbit, or else to weather conditions that could be expected in that month.
Names of the weeks and days
The Istran week is 8 half-days (4 days) long - all Istran languages employ a base 8 counting system, which makes this a logical division. The half-days alternate between daytime and night-time, with the first half-day of the week starting at daybreak. Every month contains 8 weeks except for the last month (in non-decadal orbits), which contains seven weeks.
Each week in a month has its own name which, similar to the months, can be given in long-form or short-form. The individual half-days that make up each week are not named - numbers, deployed as quantifiers to the short-form names in more informal speech, are used to indicate each half-day within the week.
| Week of the month | Short form name | Long form name | Translation |
|---|---|---|---|
| First week | o/xo demkrec | o kreac om dem | the week of the sun |
| Second week | an/a sittekrec | o kreac om glaet ac sitte | the week of the white moon |
| Third week | o/tol cyoŋkrec | o kreac tom cyoŋ ac kanó | the week of the great veil |
| Fourth week | an/a tíkekrec | o kreac om kjitto ac tíke | the week of the bright star |
| Fifth week | o/do tvelkrec | o kreac om glaet doc tvel | the week of the red moon |
| Sixth week | y/y laombkrec | o kreac om kjitto y laomb | the week of the horizon star |
| Seventh week | e/e qláckrec | o kreac em qlás xoc tzorre | the week of the northern spear |
| Eighth week | o/do epveanthemkrec | o kreac om kjitto doc epveanthem | the week of the star who wanders |
The names of the weeks refer to astronomical phenomena: the sun, red moon and white moon are easily the brightest objects in the sky, while the bright star, horizon star and wandering star are the names fgiven to the other three major planets in the Kaliedan system. The 'northern spear' is the Istran name for a line of stars near the northern celestial pole, while the 'great veil' refers to the galactic mass of stars which perpetually light up the lower latitudes of the nigh-time sky.
Times of the day
Istran Society takes an octal approach to dividing the half-day (an plex) into time periods, with each half-day divided into 8 'watches' (an ykem), which are in turn divided into 8 'periods' (an fyille), each of which contains 8 'minutes' (an sago) - all of these time divisions start at zero, not 1. Smaller divisions are shown either as a fraction of an an sago, or as a floating-point octal separated from the integer by either a hyphen or a period.
The Istran half-days traditionally start at dawn and dusk, though for more accurate timekeeping the daytime an plex starts 4 an ykem before midday.
Writing the date and time
The commonest method of writing the date in O Yis is to write the orbit number (which is always given as an octal, not a decimal), followed by the month name and the week name with the half-day of the week inserted within the week name - half-days are counted from zero, not 1, so the first half-day is not indicated while the second half day is marked using bo, the third half-day uses to, etc.
Numerically, the order is orbit - month number (counted from 1) - week number (counted from 1) - half-day number (counted from 0). The time is separated from the date by a colon and is effectively the portion of the half-day that has elapsed.
Thus for the Gevey date and time: Tedrjasu-23, 531: Dxaftcu-38 Gevile...
- X10032 o redemcleepjor xoc goat demkrec, an to ykem rec goat fyille rec to sago
- 10032 o redemclépjor xoc goat demkrec, an to ykem rec goat fyille rec to sago
- 10032 ɔ ɾəðəmsləˑpjɔɾ xɔs gɔæt ðəmkɾəs, æn tɔ ɐkəm ɾəs gɔæt fɐilːə ɾəs tɔ ʦægɔ
- 10032-3-1-5:252