The calendar of Nibirion is simpler than the earthly one: there are no months, no leap years, and no difference between the hemispheres. Everything divides evenly, which is convenient – in an adventure you can name a date without consulting a table.
| Unit | Length | Made up of |
|---|---|---|
| Year | 360 days | 4 seasons |
| Season | 90 days | 9 decades: 4 in the early season, 5 in the late one |
| Decade | 10 days | one turn of a moon |
| Day | 24 hours | hours are the same all year round |
The year, the seasons and the decades
A year holds 360 days and four seasons: winter, spring, summer, autumn. There are no months – people count in decades instead. Each season takes exactly nine of them.
A season splits in two, so the year has eight parts in all: early winter and late winter, early spring and late spring, and so on. The split is uneven: four decades fall to the early season and five to the late one.
There are no weeks. The decade did not come from arithmetic but from the sky: a moon completes its turn in exactly ten days, and counting by moons turned out to be the easiest way.
Days and sundials
A day holds 24 hours, and here an hour is a constant. The planet has no axial tilt, so sundials keep perfect time all year round: divide the circle into 24 equal segments and each one gives exactly one hour.
Everything else follows from the same fact: day and night are always roughly equal, the northern and southern hemispheres are no different from each other, and at the same latitude the weather is much the same everywhere. The climate of Nibirion is far calmer than the earthly one.
Two moons
There are two moons, and both are small: they orbit twice as close as the earthly one, yet they are so much lighter that in the sky they look two or three times smaller than the familiar disc. They run in opposite phases – when one is full, the other is new.
That is why the tides of Nibirion are weak: the moons pull the water in different directions and cancel each other out. The sea here is calm, and its behaviour is predictable decades ahead.
What makes the seasons turn
With no tilt, the seasons cannot arise the way they do on Earth. They come from a stretched orbit: the planet draws closer to its sun, then moves away again. In winter the sun looks slightly smaller than in summer, though the difference is barely visible to the eye.
A full turn around the sun takes 720 days, while the year of seasons runs to 360. There is no contradiction here: the sun sits at the middle of the stretched orbit rather than at its end. In one turn the planet passes close twice and far twice, so the seasons have time to come round twice as well.
A note – there are in fact two suns
Strictly speaking, an elliptical orbit with the sun in the middle is impossible: a star must always sit at a focus of the ellipse, never at its centre. Otherwise the planet would cross the near stretch faster than the far one, and one of the seasons would come out noticeably longer than the rest.
The answer is that there are two suns: a pair of identical stars sitting close together. Their shared centre of gravity is what ends up in the middle of the orbit, and that is what gives two close passes per turn.
From the surface of the planet this cannot be told apart: at such a distance the two discs merge into one, and the local crafts have not reached the instruments that could separate them. Only a truly stubborn scholar might think to look at the sun through cunningly chosen crystals – and notice that it pulses very faintly, changing its width.
For an adventure this is a convenient secret: two brothers – two stars, two sisters – two moons. Prophecies, cults and anything touching gods and demons hang on it well.
Why spring is not like autumn
If the seasons were set by distance to the sun alone, spring and autumn would be identical – the planet passes through the very same point. Yet they differ, and the water is what makes the difference.
Oceans are slow: they take up heat slowly and give it back slowly. When the planet draws closer to the sun, the water still holds the cold of winter – that is spring. When it moves away, the water gives back the heat gathered over summer – that is autumn. The same stretch of orbit, and yet two different seasons to live through.
How people talk about time
An ordinary person does not use dates. Long stretches are counted in seasons, short ones in moons:
- “That happened five winters ago” – that is, five years ago
- “It will be in three moons” – that is, in thirty days
Which season a people counts its years by is a matter of local custom. Some say “five winters”, others “five summers”, and the difference is a handy tell of where a stranger comes from: humans and goblins do not count alike.
An exact date, of the “on the fifth of such-and-such a month” sort, is already beyond an ordinary townsman. The educated classes, on the other hand, have their own names for decades and seasons, and handling them is itself a mark of learning. Among the elves it sounds like this: “on the fifth day of Eyvor” – and any lettered elf knows that Eyvor is the twenty-fifth decade, which means late autumn.
A note – how to use this at the table
The decade is a handy step for deadlines. “The caravan leaves in two moons”, “hired for a decade”, “three decades left until the feast of late winter” all sound local and are still immediately clear at the table.
You do not need to invent names for the decades in advance. It is enough that an educated speaker names one and a plain one asks back, “and that is how many winters?” – the difference in counting will show the difference in birth and schooling by itself.
An even calendar suits the game master too: 360 days, 36 decades, no corrections. A date can be written down as a season and a decade, with no fear that the count will drift.