Cold Dew寒露

Cold Dew (寒露, Hán Lù) is the seventeenth of the twenty-four solar terms and, in the BaZi calendar, the term that opens the 戌 month. It is an astronomical instant rather than a day: the moment the sun reaches 195° of ecliptic longitude, which falls on 8 or 9 October depending on the year.

Its name is a direct escalation of the term two places before it, White Dew (白露), which sits in the same slot of the seasonal cycle a month earlier. Both name the same morning moisture; the difference the name is tracking is that the dew has gone from merely noticeable to properly cold, a sign the season has tipped past its mild stretch.

Astronomically Cold Dew sits at the midpoint between the Autumn Equinox and Frost's Descent, deep enough into autumn that the sun's arc is visibly lower and days are shortening fast in the northern hemisphere. In the agricultural calendar it is traditionally read as the point where the last of the autumn harvest needs finishing and where migratory birds and insects prepare for the colder stretch ahead.

Cold Dew is a 節 — a month-opening term — so at the instant the sun crosses 195° the month pillar's branch becomes 戌 (Xū). This is one of the twelve month-openers that structure the BaZi year; unlike Beginning of Spring, it moves only the month pillar and never the year.

This site's engine confirms the mechanism directly. Scanning 2026 day by day, the month pillar steps into 戌 by 9 October that year — the switch is already showing in the reading taken at noon that day, since the precise instant of the term can fall a little earlier or later within the same date. A birth anywhere from that instant until Frost's Descent two weeks later carries a 戌 month pillar because of this term, not because of the calendar date on its own.

White Dew (白露) — The twenty-four solar terms. The other 節 with "Dew" in its English name, one month earlier and opening the 酉 month rather than 戌. Both are month-openers, so neither can be dismissed as the lesser of the pair — the difference is which branch they open, not which one "counts" more in a chart.