Avalon Standard Calendar

Currently unofficial lore, and in progress.

Structure

The Avalon Standard Calendar was the official calendar system of the Illuminate Republic and now of the Avalon Alliance. It splits each year (one full orbit around Solakku), on Avalon into 895 days. This is equal to ~13 Earth-years and ~128 Earth-hours per day. These days are then organized into 20 seasons, of which 15 are 45 days long, and 5 are 44 days long. It is every third month which is only 44 days long, with the first instance of this being the third month of the year.

For everyday scheduling, there is also a division into 12 day long cycles, a number roughly based on the conjunction of Avalon and Mov. Every seasons is about 3.75 cycles long, but seasons and cycles are not forced to be aligned, making the behavior similar to how weeks are not aligned to months in the Gregorian calendar.

Year 0, Day 0 was defined as being the day the rule of law for the first Illuminate nation was signed, even though the calendar was not introduced until centuries after the fact, and made the official calendar of the Republic much later in 309. Years before this day are simply expressed as negative numbers.

Due to Avalon’s movement around Solakku, its Sidereal period is ever so slightly shorter than its true rotation period, leading to a continuous buildup of error in time measurement, which eventually needs to be corrected by inserting an additional day in the year. These leap years occur on every even-numbered year and turn the first 44-day long season of that year into a 45-day long season.

Written dates are formatted as [day of season], [season] [year] in the most compact form, for example: 23rd, 5th 505. But another commonly used format is [day of cycle].[cycle of season], [season] [year], for example: 10.2 3rd 497.

History

The Avalon Standard Calendar was originally derived as the Astronomer's Calendar, which was based on the perceived movements of the stars throughout the year with the primary purpose of tracking and planning astronomical observations. The exact year when the first version of this calendar was drafted is unknown as the original calendar did not count years, but was likely around the year 240 after the formation of the Illuminate.

To create this calendar, an existing ancient calendar, based on the movement of Crest throughout the year, was modified. As Crest slightly moves along its own orbit over each year, calendars based on its movement are not perfectly aligned to Valaya's orbital period and drift over time. The Astronomer's Calendar intended to correct for this.

Though originally only popular within Astronomy circles, this new calendar began gaining mainstream appeal due to its simplicity compared to moon calendars and perceived superiority as being based in scientific observation. Its first use in an official capacity by the Illuminate was recorded in the year 244 and it became a de-facto standard over the following years. It was not until the year 309 when it became the official standard calendar of the Illuminate Republic, though by this point its use was already widespread.

Modern use

As this calendar is based around the orbits of specifically Avalon and Valaya, it is of little use for nations existing on other planets or moons, which have tended over time to develop their own calendars. The Avalon Standard Calendar is still used within all territories of the Avalon Alliance, and some other nations, however. It is also to be used in all standard communication within the Solakkian Union, and all official recordkeeping and by historians.

Spacecraft, space stations and other habitats which need to establish an artificial day/night cycle also tend to simulate Avalon’s day length, and as such use the Avalon Standard Calendar.