Spring Equinox (Chunfen 春分): dates, pentads and meaning
Fen (分) means to divide. The Sun is overhead at the equator, day and night are nearly equal everywhere, and the ninety days of spring are split in half.
Spring Equinox dates, 2026–2035
| Year | Date | Time (Taiwan, UTC+8) | Month pillar |
|---|---|---|---|
| 2026 | March 20 | 22:45 | still Xin-Mao 辛卯 month |
| 2027 | March 21 | 04:24 | still Gui-Mao 癸卯 month |
| 2028 | March 20 | 10:17 | still Yi-Mao 乙卯 month |
| 2029 | March 20 | 16:01 | still Ding-Mao 丁卯 month |
| 2030 | March 20 | 21:52 | still Ji-Mao 己卯 month |
| 2031 | March 21 | 03:40 | still Xin-Mao 辛卯 month |
| 2032 | March 20 | 09:21 | still Gui-Mao 癸卯 month |
| 2033 | March 20 | 15:22 | still Yi-Mao 乙卯 month |
| 2034 | March 20 | 21:17 | still Ding-Mao 丁卯 month |
| 2035 | March 21 | 03:02 | still Ji-Mao 己卯 month |
Times computed by our calendar code (UTC+8); they agree with an astronomical calculation to within about a minute. Between 1901 and 2100, Spring Equinox always falls on March 19–22. Subtract 8 hours for UTC.
The three pentads of Spring Equinox
| Sign of the season | When | |
|---|---|---|
| First pentad | Swallows return (玄鳥至) | about days 1–5 after Spring Equinox |
| Second pentad | Thunder is heard (雷乃發聲) | about days 6–10 after Spring Equinox |
| Third pentad | Lightning first appears (始電) | about days 11–15 after Spring Equinox |
The ancients split each solar term into three pentads (hou 候) of about five days each, and marked them by changes in birds, animals and plants: seventy-two pentads a year. These follow the standard list in Wu Cheng's Yuan-dynasty Collected Explanations of the Seventy-Two Pentads. They were observed in the Yellow River basin, so they do not always match what you see in Taiwan, let alone elsewhere. Some, like hawks turning into doves, record old beliefs rather than biology.
Spring Equinox in the sky: where the Sun is
The solar terms follow the Sun along the ecliptic: one term for every 15°, and Spring Equinox is the moment the Sun reaches longitude 0°. In 2027, at Spring Equinox the Sun sits against the stars of Pisces (drowned out by daylight, of course). That day in Taipei the Sun rises at 05:57 and sets at 18:05, about 12 h 8 min of daylight. Daylight is slightly longer than 12 hours because atmospheric refraction lifts the Sun into view early and keeps it visible late, and sunrise and sunset are timed by the Sun's upper edge.
What Spring Equinox means in BaZi
Spring Equinox is a qi (氣), or "middle term" (中氣): it falls in the middle of the Mao month (卯), so the BaZi month pillar does not change here; it is the same Mao month before and after. Middle terms matter in the calendar for another reason: a lunar month with no middle term in it becomes the leap month.
BaZi months are not counted from the lunar new moon but from the jie terms: Start of Spring, Awakening of Insects, Pure Brightness, Start of Summer, Grain in Ear, Minor Heat, Start of Autumn, White Dew, Cold Dew, Start of Winter, Major Snow and Minor Cold each open a month. If you were born on the day of a jie term, within a few hours of it, your month pillar (and for the Start of Spring, your year pillar too) can shift by one; it depends on the exact time. See solar term boundaries, and for how the month's heavenly stem is worked out, the month pillar.
Look up the solar terms for any year
Pick a year to list the exact time of all 24 solar terms (Taiwan time, UTC+8) and the month pillar each jie term starts. Add a month and day, such as a birthday, to see which solar-term period it falls in and its month pillar. Everything is calculated in your browser.
The times come from the same calendar code our BaZi charts use; for 1901–2100 they agree with an astronomical calculation to within about a minute. If you were born within minutes of a term changing, see solar term boundaries.
The terms before and after
The previous term is Awakening of Insects; the next is Pure Brightness.
A straight word: solar terms are astronomy; luck is something else
The twenty-four solar terms divide the year by the Sun's position on the ecliptic, and their times can be computed to the second. BaZi uses them to change the year and the month; that is a rule of calculation. A solar term carries no good or bad luck of its own, and no term is a "better" one to be born in: a chart is read as a whole, by its Five Elements and Ten Gods. Everything on this site is for reference and entertainment.
Solar terms set the month; the month sets strength
Enter your birth date for a free Four Pillars chart and see your month element and the balance of your whole chart.
Spring Equinox: common questions
What date is Spring Equinox in 2026?
In 2026, Spring Equinox falls on March 20 at 22:45 Taiwan time (UTC+8); in 2027 it is March 21 at 04:24.
Why does Spring Equinox move from year to year?
A solar term is the moment the Sun reaches a set longitude, here 0°. A year is about 365.24 days, not a whole number, and leap years reset the count, so the date drifts within a few days. From 1901 to 2100, Spring Equinox always falls on March 19–22.
What are the three pentads of Spring Equinox?
First: Swallows return (玄鳥至); second: Thunder is heard (雷乃發聲); third: Lightning first appears (始電). They follow the standard Yuan-dynasty list.
What does Spring Equinox do in a BaZi chart?
It is the middle term of the Mao month, so the month pillar does not change. BaZi changes months only at the jie terms.