For my conworld, Kalieda ...
Do the people live on Earth, or on another planet? If the latter, what is the astronomical environment of the planet (moons, seasons, etc.). How does the timekeeping system handle annual variation in the length of a day? (Since Earth's orbit is nearly circular, we can afford to ignore this here.)
Kalieda takes 380.41 days to complete an orbit around its primary.
- Average diameter: 13,029km
- Density: 5,498kg/m³
- Minimum distance from Wage: around 145 million km
- Maximum distance from Wage: around 149 million km
- Surface gravity: 10.04m/s²
- Axial tilt: 16.7°
- Average surface temperature: 289K
Kalieda has two moons: white Leprhaakhe has an orbit of approx 8.23 days, while red Tuustinte takes a more leisurely 35.91 days (again, approx). Both are (mostly) tide-locked but currently don't have an orbital resonance, which leads to small irregularities in their orbital periods - neither has much influence on any Kaliedan calendar system, which are all resolutely solar-based.
What celestial events are of importance to the calendar? (Different cultures might have different priorities even on the same planet; e.g., seafaring folk would care very much about the moon, while polar-region dwellers might not even have a concept of a "day").
All the major calendars use the northern spring (southern autumn) equinox as the starting point for their calendrical years.
Is there a notion of time zones or standard time? How does the "international date line" situation work?
Although the humans living on the planet have long forgotten their extraKaliedan origins, it's likely that the colonisers decided to set the meridian as the longitudinal arc that passed through the southernmost point of the largest continent - and the convention has stuck ever since. Given that for most of the planet's human history the vast majority of people lived on the two continents bisected by the meridian, this was not a problem.
However, since the Disaster, all civilisations on the largest continent have collapsed entirely and the civilisations on the northern continent are remnants; the most populous continent is now the one bisected by the 'international date line' (meaning 'east' is west, and vice versa). There's talk of moving the meridian, but no agreement yet about where the new line should be drawn.
Given that most settlements and cities work on local time, and there's no single agreed calendar for the whole continent, this is not a big problem for anyone other than scientists. The new-fangled internets use the local time in the city of Ramaja as an informal reference point.
Are there any non-celestial periods that are reckoned? (E.g., weeks). How is the day divided? When is the day considered to begin? (Sunrise, sunset, midnight?). Where did the calendar/timekeeping system originate? Religious functions, government decree, something else?
It varies between calendars -
See this page of the Encyclopaedia for more info
Gevey calender - a local adaption of the Falah standard calendrical system.
O Yis calendar - a form of the Istran calendrical system.