Eracustan Calendar

The Eracustan Calendar is a calendar that is used for most spacefaring civilizations, and used for local timekeeping on voidships and space stations. It was introduced by one of the many independent precursor nations on Eracustas from approximately 34th-38th Century BCW. It is a Lunar Calendar in nature, meaning it uses the phases of Eracustas' two moons, Dentar and Allus, to determine weeks, months and years.

The Eracustan Calendar is divided into 320 days per year (corresponding to Eracustas' orbital peroid), 16 months per year. Each month has 20 days, which are grouped into 4 weeks, with 5 days each. Dentar has an orbital period of 20 days, while Allus has 80 days. As such, Dentar's first of three consecutive full moons is the start of a new month. If both Dentar and Allus are shown as full moons, then it is the start of one of the four Quadrocenes. Quadrocenes are four equally divided measurements of time equaling 80 days each, and together make a full 320-day Eracustan year.

For a long time, it was thought that each Quadrocene was an Eracustan year, according to the double full moons. However it was discovered sometime between the 34th and 38th Centuries BCW that Eracustas had a very slight temperature shift. At the north pole, the air would receive on average -1.0°C during the start of the year, then rise to 2.0°C mid-year before falling again and repeating. This change correlated to the small axial wobble that Eracustas had as it orbited Sedaurus.