Common Era calendar
The Common Era calendar, also known as the Gregorian calendar or the Christiean calendar, is the primary international standard calendar used among countries on Urth. While other countries, such as Asendavia, Alksearia, The Oan Isles and others use their own calendars internally (eg., Oan Lunar Calendar), nearly every country uses the Common Era calendar at least for the purposes of international commerce and diplomatic negotiations. The calendar was first devised and introduced by the International Common Calendar Conference that took place at Rilanon, Christie Island, in June and July of the year 1701. It has also been adopted by several countries who did not send delegates to the conference. The document produced by the conference is known as the Christie Decree.
The calendar is a solar calendar in which a year is an average of 365.2425 days in length. An extra day of the year, called a "leap day," is added to the calendar according to rule in order to keep the calendar in alignment with the seasons. Years with this additional day are known as "leap years."
The rule for leap years as established by the Decree is: "Every year that is exactly divisible by four is a leap year, except for years that are exactly divisible by 100, but these centurial years are leap years if they are exactly divisible by 400." This means that, for example, the years 1700 and 1800 are not leap years, but 1600 and 2000 are.
By the turn of the 18th century, global commerce over land and sea had become prevalent enough that the need for a standard way to track dates became apparent. Prior to that date, most countries used their own calendars, and any negotiations between countries would need to reckon dates in both systems. Each calendar had its own dates of origin as well as own rules for determining the length of days and years. For instance, the traditional Akronist liturgical calendar is a lunar one with days beginning at sundown and months reckoned only by the phase of the moon, which made it complicated to convert dates into a solar calendar system where days began at sunrise and months being a fixed number of days.
One of the primary sticking points among the negotiators devising the calendar was choosing where and why to place "year one." The epoch had to be unconnected to the history of any one particular country, religion, or historical figure. Eventually, the delegates settled on using the date that a meteor impacted the Urth in mid-winter 1,701 years prior to the date of the conference, because it was an event that was recorded by various cultures across the world and, therefore, could be calculated with precision.
The meteor's approach was seen as a bright streak across the sky by people across the world, and was noted as an omen (of either good fortune or ill) in several different cultures. The meteor struck in what is now Tavaris and had an aequatorial approach that made the streak visible in both the Northern and Southern hemispheres. However, more notable and even more widely recorded was that the meteor's impact created a massive dust cloud that darkened the skies across the planet, negatively impacting temperatures, agriculture, and navigation worldwide. Academics believe that a smaller part of that meteor broke off and struck the area of Akas Akil, Ashura, Packilvania, an event which is marked on the Paxist liturgical calendar and adds to the religious significance of the Memorial of the Jovian Gate.
Impelanzan historical records show a shift from sea-based to land-based travel and commerce after the impact because the dust and ash obscured the stars in the night sky by which they navigated at sea. The records of the Tavari people who lived in the area where the meteor hit noted a massive famine in the year of the impact, which they believed to be a fragment of the moon falling to Urth. The island on which the meteor hit is named the Greater Tear of the Moon (there is also the Lesser Tear of the Moon, a smaller, neighboring island), named after the event, and the island was held to be cursed and therefore remained intentionally uninhabited for centuries. In the current day, the islands are home only to a few scattered Akronist monastic communities.
Delegations from several nations engaged in international commerce met at Rilanon, Christie Island on June 30th, 1701. Over the course of three weeks, the attendees worked to devise a standard calendar that would be acceptable for every nation. The delegates elected Staynish astronomer Gregory Brilliant to be the presiding officer of the conference, which is why the Common Era calendar is also sometimes known as the Gregorian calendar.
Approximately half of the delegates were astronomers, historians, and other academics who did the primary work of calculating the epoch and devising the rules. The other half of the delegates were ministers, ambassadors, and political officials from various governments, who did the primarily political work of convincing their counterparts to accept and use the calendar internationally. Delegates from Bana, Cryria, Duominzu, Great Morstaybishlia, Rosalica, South Peragen, Packilvania, and Tavaris attended the conference.
Christie Island's hosting of the international conference would lead to the country having an international reputation as a neutral meeting ground. Christie Island would later be selected as the location of the Prime Meridian, by which other lines of longitude were numbered and how time zones were delineated under the Universal Time at Christie (UTC) standard.