Edo-Era Time Names Converter
Enter a modern time to convert it into the Edo-period Japanese time system — the Hour of the Rat, the eerie "third quarter of the Ox," noon as "nine bells," and more. Includes a reverse lookup table too.
Edo-Era Time Reference Table (Modern Time → Old Names)
| Order | Hour name | Bell count | Approximate modern time |
|---|---|---|---|
| 1 | Hour of the Rat (子の刻) | Nine bells (九つ) | 23:00 – 01:00 |
| 2 |
Hour of the Ox (丑の刻)
The "third quarter of the Ox" (丑三つ時, ushimitsu-doki) is the famously eerie hour said to be haunted by ghosts, around 2:00–2:30 a.m. |
Eight bells (八つ) | 01:00 – 03:00 |
| 3 | Hour of the Tiger (寅の刻) | Seven bells (七つ) | 03:00 – 05:00 |
| 4 | Hour of the Rabbit (卯の刻) | Six bells (六つ) | 05:00 – 07:00 |
| 5 | Hour of the Dragon (辰の刻) | Five bells (五つ) | 07:00 – 09:00 |
| 6 | Hour of the Snake (巳の刻) | Four bells (四つ) | 09:00 – 11:00 |
| 7 | Hour of the Horse (午の刻) | Nine bells (九つ) | 11:00 – 13:00 |
| 8 | Hour of the Goat (未の刻) | Eight bells (八つ) | 13:00 – 15:00 |
| 9 | Hour of the Monkey (申の刻) | Seven bells (七つ) | 15:00 – 17:00 |
| 10 | Hour of the Rooster (酉の刻) | Six bells (六つ) | 17:00 – 19:00 |
| 11 | Hour of the Dog (戌の刻) | Five bells (五つ) | 19:00 – 21:00 |
| 12 | Hour of the Boar (亥の刻) | Four bells (四つ) | 21:00 – 23:00 |
Tips for the Edo-era time converter
- This tool uses a simplified fixed-hour model (2 hours per period) for clarity. In reality, Edo-period Japan used a variable-hour system where the length of each period shifted with the seasons, so a period was longer in summer daytime and shorter in winter.
- "Shōgo" (正午, noon) literally means "the true middle of the Horse hour," and it's the direct origin of the modern word for noon.
- The famously spooky phrase "even the trees and grass sleep at ushimitsu-doki" — often heard in period dramas and ghost stories — refers to the time this tool displays as roughly 2:00–2:30 a.m.
- "Akemutsu" (明六つ, dawn's six) and "kuremutsu" (暮六つ, dusk's six) referred to the "six bells" of the Rabbit and Rooster hours, and were used as rough markers for sunrise and sunset.
Frequently asked questions
Side Note — the "Bell of the Hours" and Edo's sense of time
In the Edo period, ordinary people learned the time from the "bell of the hours" (時の鐘), rung at temples and around castle towns. The bell struck a count of nine, eight, seven, six, five or four, decreasing by one every two periods — an unusual counting system. It's widely believed that the word "oyatsu" (おやつ, meaning an afternoon snack today) comes from the custom of eating a snack around the "eight bells" period, roughly 2 p.m.
The fixed "2 hours per period" model used by this tool is called the "teijihō" (定時法, fixed-hour system), a simplified model favored for its clarity in education. In everyday Edo-period life, the dominant system was actually the "fujōjihō" (不定時法, variable-hour system), which divided daylight hours into six equal periods and nighttime hours into a separate six. As a result, a daytime period was longer in summer and a nighttime period was longer in winter — a sense of time fundamentally different from a modern clock.
The shift from the variable-hour system to the fixed-hour system (today's 24-hour clock) happened alongside the calendar reform of 1872 (Meiji 5). The unit of "koku" (刻), which had stretched and shrunk with the seasons until then, was replaced by the uniform unit of the "hour." This change went far beyond a simple calendar reform — it's said to have transformed the very rhythm of ordinary people's daily lives.