Frequently asked
What is 72 Japanese Seasons?
A clock for Japan's traditional way of keeping time, for iPhone and Apple Watch. It shows the twelve toki (double-hours) that stretch and shrink with the sun, the 72 kō microseasons grouped under the 24 sekki, and teaches the kanji behind them — kanji, romaji and English everywhere.
What are toki, sekki and kō?
Toki are the old double-hours: six from sunrise to sunset, six from sunset to sunrise, so their length changes with the season. Sekki are the 24 solar terms of the year, and kō are the 72 five-day microseasons within them, like "bush warblers begin to sing".
Does it need my location or the internet?
No internet is needed — everything is computed on your device from the sun's position, so it works for any year with no updates. Location is used only to work out your local sunrise and sunset, and it stays on your device. Without it, the app uses a fixed Tokyo reference. See the privacy policy.
Is there an Apple Watch app?
Yes. There's an Apple Watch app with complications — a 12-tick toki dial, plus a sekki and kō complication with the day count — as well as Lock Screen and Home Screen widgets on iPhone.
How accurate is the calendar?
The sekki and kō come from the sun's ecliptic longitude, and sunrise and sunset use the standard NOAA equation for your date and location — accurate to about a minute for roughly 1800 to 2100, and it never expires because it is an algorithm, not a lookup table.