A GNOME Shell extension that keeps time the way Edo-period Japan did: in unequal temporal hours (不定時法, futeijihō). The top bar shows a single kanji — the current hour of the twelve earthly branches. The popup lists the full cycle of twelve hours, their bell counts, boundaries, and today's dawn and dusk.
No notifications, no network requests, silent by default. One glyph in the panel — and, if you switch it on, a temple bell.
The extension implements the variable-hour system used in Japan until the Meiji calendar reform of 1873. Four principles govern the computation.
Daytime (dawn to dusk) is divided into six equal toki; nighttime (dusk to dawn) into six more. Because the two spans are divided independently, a daytime toki and a nighttime toki are almost never the same length, and both drift continuously with the seasons. At the latitude of Vilnius the contrast is dramatic: near the summer solstice a daytime toki stretches past three hours while a nighttime toki shrinks below one; at the winter solstice the proportions invert. This seasonal breathing is not a defect to be corrected but the entire point of the system — wadokei clocks were built with movable hour plates or dual foliots precisely to track it.
The bell time is the shōkoku (正刻), the midpoint of the toki — not its boundary. This is why solar noon is called 正午, "exact Horse": it falls in the middle of the hour of the Horse, and solar midnight (正子) in the middle of the hour of the Rat. Consequently the hour boundaries lie halfway between adjacent bells. The extension computes bells first — dusk and dawn anchor the runs, each run's bells spaced one unit apart — and derives boundaries from them.
The hours of the Rabbit (卯, centered on dawn) and the Rooster (酉, centered on dusk) straddle the day/night boundary. Their first and second halves therefore run at different rates: half a night-unit glued to half a day-unit. In July at 54°N the Rooster lasts about 120 minutes while its all-day neighbors run 182 and its all-night neighbors 59. This is the historically correct behavior, not an artifact.
Ake-mutsu (明け六つ) and kure-mutsu (暮れ六つ) were not sunrise and sunset but the onset of usable light — traditionally, when the lines of one's palm become visible, corresponding to the sun several degrees below the horizon. The extension approximates this with a constant offset, a configurable offset (36 minutes by default) before sunrise / after sunset. A fixed offset is a simplification (the rigorous definition is a solar depression angle, whose clock-time equivalent varies with season and latitude); set it to 0 in preferences for plain sunrise/sunset if you prefer astronomical purity over civil convention.
Hours are announced by 9 down to 4 strikes, twice per cycle — 9 at the Horse (noon) and the Rat (midnight), descending to 4, then restarting. The traditional derivation multiplies the yang number nine by the hour's index and keeps the last digit: 9, 18→8, 27→7, 36→6, 45→5, 54→4. Counts one through three were reserved for temple signals, which is why no hour strikes fewer than four.
Sunrise and sunset are computed locally with the standard low-precision
solar algorithm (the SunCalc formulation: solar mean anomaly → ecliptic
longitude → declination → hour angle), using the conventional altitude of
−0.833° to account for atmospheric refraction and the solar radius.
Accuracy is on the order of a minute, which is well below the natural
fuzziness of the "lines on your palm" convention. All times are handled in
the system timezone via ordinary Date arithmetic, so DST transitions are
absorbed automatically.
Above the polar circles the division is undefined on days without a sunrise or sunset — and, at slightly lower latitudes, a large dawn/dusk offset can consume a short midsummer night entirely. Both cases are detected, and the extension shows an em dash and says so in the popup, rather than inventing hours the system never defined.
Coordinates come from GeoClue at city-level accuracy when location services are enabled (Settings → Privacy → Location). GeoClue is loaded lazily and cancelled cleanly on disable; if it is unavailable, denied, or disabled, the manual coordinates from preferences are used instead (default: Nihonbashi in Tokyo, the zero milestone of Edo — a deliberately conspicuous placeholder). The popup's last line always shows the active coordinates and their source.
All options live in GSettings and are edited through the standard
preferences window (the Extensions app, or gnome-extensions prefs wadokei@tianci.vilnius) — nothing is configured by editing code:
- Language — follows the system locale by default, or can be forced to English, Russian, Lithuanian, Belarusian, Chinese, or Japanese independently of the system language. The Chinese and Japanese locales use their native horological vocabulary (未时/九响, 未の刻/九つ, 明け六つ/暮れ六つ, 正刻). The twelve branch characters (子丑寅卯辰巳午未申酉戌亥) are hanzi and are intentionally never translated — they are the interface.
- Time format — 12-hour or 24-hour; follows the GNOME clock setting by default.
- Day boundary — how dawn/dusk are defined: the Edo depression angle 7°21′40″ (default), civil twilight (6°), plain sunrise/sunset, or a fixed offset in minutes.
- Location — GeoClue geolocation on/off, with manual coordinates used when it is off or unavailable.
- Chimes — off by default. When enabled, the bell strikes the traditional count of each hour (9…4) at its center, 正刻, through the GNOME Shell sound player. Any audio file can be chosen; the bundled default is a temple bell recording by tec_studio (freesound.org #668647, CC0).
git clone https://github.com/tedvask/wadokei.git
cd wadokei
make installLog out and back in (Wayland), then:
gnome-extensions enable wadokei@tianci.vilniusRequires GNOME Shell 48–50. Developed and tested on Fedora 44 / GNOME 50.
| Target | Effect |
|---|---|
make pack |
build the zip via gnome-extensions pack (schemas compiled automatically) |
make install |
pack and install for the current user |
make clean |
remove build artifacts |
The panel indicator updates every 30 seconds; the popup also refreshes on open. The extension holds no state between sessions and touches nothing outside the Shell process.
GPL-3.0-or-later. See LICENSE. The bundled bell sound
(assets/bell.oga) is CC0 (public domain), by tec_studio on freesound.org.