someday i'd like to start using a calendar system that goes something like this: each new year begins on the winter solstice. each new month begins on the new moon. when a new year starts in the middle of a month, the date number doesn't roll over. i have nothing in mind for what the year number would represent, but using a meaningless number for the year, here's an example for the system in the northern hemisphere:
| gregorian | this thing | |
|---|---|---|
| 2024-11-30 | 0999-12-28 | |
| 2024-12-01 | 0999-13-00 | [α] new moon |
| 2024-12-02 | 0999-13-01 | |
| ⋮ | ⋮ | |
| 2024-12-20 | 0999-13-19 | |
| 2024-12-21 | 1000-00-20 | [β] winter solstice |
| 2024-12-22 | 1000-00-21 | |
| ⋮ | ⋮ | |
| 2024-12-29 | 1000-00-28 | |
| 2024-12-30 | 1000-01-00 | [γ] new moon |
| 2024-12-31 | 1000-01-01 |
for most of the year, the days count up as usual. at [α], a new moon, a new month begins; this system considers there to be a "0th day" and "0th month" because one full day/month hasn't yet passed. at [β], the winter solstice marks the start of a new year, but the day of the month doesn't change -- in a way, year 999's month 13 and year 1000's month 0 are two ends of the same month. finally, things continue as normal from there, entering month 1 on the new moon at [γ].
this system is intentionally hard to use on computers, across hemispheres, or for doing math; it's intended for a manual, individual scale. i don't really have any reason to use it at the moment, especially not with a concrete idea of when the epoch (year 0) should be, but it'd be cool to develop this system and use it for something someday.
these ideas came from multiple places; i don't claim to have invented all of this myself. of course, solstice-based years and moon-based months are incredibly common across the world. the japanese calendar system, based on the currently reigning emperor, switches year names mid-year when a new emperor takes the throne, but the month and day continue counting up without resetting. the sts'ailes nation uses a similar system to mine but stops counting after 10 months, so there's a period of time before the next salmon migration where the days just aren't numbered.