🧮 Calculators & Daily Life

24 Solar Terms (Nijūshi Sekki)

Pick a year to list the dates of the 24 solar terms — the traditional calendar points, defined by the sun's position, that mark the seasons in Japan. See instantly which term today falls in. Everything is computed in your browser.

TermDateSun's longitudeMeaning

How to use

Enter a year (or use the Prev / Next buttons) to list that year's 24 solar terms. Above the table you'll see which term today falls in. "Copy list" exports the dates as plain text for planning or reference.

What are the 24 solar terms?

The nijūshi sekki divide the sun's yearly path (the ecliptic) into 24 segments of 15°, each with a poetic seasonal name. The system came to Japan from China and still shapes everyday life: the equinoxes (Shunbun, Shūbun) are national holidays, Risshun marks the calendar start of spring (the day before is the Setsubun bean-throwing festival), and Tōji — the winter solstice — comes with yuzu baths and pumpkin. Because the terms follow the real sun, each date shifts by about a day from year to year. Seasonal greetings in formal Japanese letters are also chosen by the current solar term.

Examples

  • Risshun 2026 → February 4. The day before is Setsubun.
  • Risshun 2025 → February 3 (a leap-cycle year where it lands one day early).
  • Shunbun / Shūbun → the spring and autumn equinoxes, both national holidays in Japan.
  • Geshi / Tōji → the longest and shortest days of the year.

FAQ

Is my data sent to a server?
No. All solar-term calculations run in your browser; nothing is transmitted or stored externally.
Do the dates change from year to year?
Yes. The 24 solar terms are defined by the sun's apparent position (every 15° of ecliptic longitude), so each date can shift by a day between years. In some years Risshun falls on February 3 instead of 4 (2021 and 2025, for example).
How are the dates calculated?
The sun's apparent longitude is computed astronomically (a truncated VSOP87 theory) and dates are judged in Japan Standard Time. Results were cross-checked against Japan's National Astronomical Observatory almanac and agree within about a minute.
What period does "today's term" cover?
Each term runs from its own date until the day before the next term. For example, the Shōsho (minor heat) period lasts from the Shōsho date to the day before Taisho (major heat).
Which years are supported?
Years 1900–2099. Official dates for Japan are published each February for the following year by the National Astronomical Observatory.