Calendar
A calendar that runs on from today: a month grid, a year wheel, a Moon drawn for every day, then a stream of what is coming. Every date is computed from a rule in the browser, and every festival has its evidence graded.
Why the dates move
Solstices and equinoxes are instants. They drift through the calendar because the tropical year, the year of the seasons, is not a whole number of days, and the leap-year rule corrects that drift in steps rather than continuously.
| Year | Instant (UTC) |
|---|---|
| 2020 | 2020-06-20 21:43:31Z |
| 2021 | 2021-06-21 03:31:53Z |
| 2022 | 2022-06-21 09:13:45Z |
| 2023 | 2023-06-21 14:57:22Z |
| 2024 | 2024-06-20 20:50:58Z |
| 2025 | 2025-06-21 02:42:17Z |
| 2026 | 2026-06-21 08:25:00Z |
| 2027 | 2027-06-21 14:10:33Z |
The three cross-quarter datings
A cross-quarter day falls between a solstice and an equinox, and there are three defensible ways to say when. The traditional reckoning names a fixed calendar date. Theastronomical midpoint is the instant the Sun reaches the midpoint in longitude. The temporal midpoint is the instant halfway in time between the two surrounding points. It differs from the astronomical midpoint because Earth's orbit is an ellipse and Earth's speed along it varies.
These can differ by several days. Every year page shows all three, side by side, with the difference stated. See Cross-quarter days for which sources use which, and The Wheel of the Year for where the eight-station scheme came from.
Year tables and downloads
- 2015
- 2016
- 2017
- 2018
- 2019
- 2020
- 2021
- 2022
- 2023
- 2024
- 2025
- 2026
- 2027
- 2028
- 2029
- 2030
- 2031
- 2032
- 2033
- 2034
- 2035
- 2036
- 2037
- 2038
- 2039
- 2040
Each year is also downloadable as an .ics calendar file. That is how this site delivers correct local times without running any code in the browser: the file carries true instants, and a calendar application places them in whatever zone the reader is in.