Amserlen awyrog (Ffynhonnell for “the sky-like/heavenly calendar”) is the calendar used by the Fey in my current worldbuilding project. I am sharing it here because it took a fair amount of effort to figure out.
It is a purely lunar calendar; one (normal) year is 354 days, which means there is a solar-seasonal drift of 11.25 days. This is completely acceptable and no attempt is made to correct the calendar such that the solar seasons are at the same time every year. The calendar does acknowledge the solar seasons, but otherwise is a purely lunar calendar, and is thus primarily concerned with lunar drift. Below I will detail the details regarding how time is counted, solar and lunar seasons, and corrections I make.
There are 12 lunar months. Each month has 29.5 days – they alternate between having 29 days and 30 days.
Each day has 16 hours. There are 90 minutes per hour. However, the length of a minute remains the same; thus, there are a different number of hours per day, and minutes per hour. Minutes are the same length (and seconds too), but the hours are a different number of minutes in length. Therefore, the number of minutes in a day remains the same as the gregorian calendar, even though the number of hours is different.
There are two sets of seasons; lunar seasons and solar seasons. This is because the length of a lunar and solar year are different. Although this is a purely lunar calendar, the solar seasons impact everything in the world so universally that the calendar must track them.
Thus, there are two summers; a solar summer and a lunar summer. Two winters in the same way. The solar seasons are based on the solar year, and the lunar seasons are based on the lunar year. They are not in sync, and they drift from each other as a result. A lunar summer may happen in a solar spring.
The solar seasons work the same as they do in our calendar; they begin on the solstices and equinoxes, and are at the same time every solar year. The lunar seasons, however, drift away from the solstices; a lunar summer can be in the solar winter.
There arefour lunar seasons that each happen once per year. They occur every three months, and each one has a “dominant” moon phase; what this means is that they begin and end upon a specific moon phase.
The lunar spring begins on the first quarter moon of the first month and ends on the first quarter three months later. The lunar summer begins on the full moon of that third month and ends on the full moon in the sixth month. The lunar fall begins on the second quarter moon of the sixth month and ends three months later. And finally, the lunar winter begins on the following new moon of that month and ends three months later.
Below is a table that is probably easier to take in than that paragraph of text directly above this sentence:
| lunar season | moon phase | lunar month |
|---|---|---|
| spring | first quarter | 1st-3rd |
| summer | full moon | 3rd-6th |
| autumn | second quarter | 6th-9th |
| winter | new moon | 9th-1st |
This means that there is a small amount of time between seasons while the moon’s phase is in limbo. These periods are called “pilgrim seasons”.
The drift between the solar and lunar year is not a concern of this calendar; the solar seasons begin at a different time each year, and that is perfectly okay in this system.
However, the lunar month is not truly 29.5 days in length. It differs from month to month, but in fact averages out to 29.53059. As a result, a leap year must occur 11 times in a 30 year cycle. Each leap year has a single “phase correction day” that occurs at the end of the 12th month.
Without this phase correction day, the calendar would drift 0.36708 days every year, or 11.0124 days every 30 years.
This leap year occurs 11 times, on months 2, 5, 7, 10, 13, 16, 18, 21, 24, 26, and 29. After the 30th year the count resets.
| year | days |
|---|---|
| 1 | 354 |
| 2 | 355 |
| 3 | 354 |
| 4 | 354 |
| 5 | 355 |
| 6 | 354 |
| 7 | 355 |
... etc. Through 30.
If I ever brush the dust off my python and java, I would love to make a little converter that would convert between gregorian and Amserlen Awyrog. I do plan on using this in my story if I ever get around to writing the ruddy thing instead of just worldbuilding into oblivion. Time will tell! Also I need to think up names for the months. I've been thinking about it for weeks but I am clueless as to what I want to name them.