Bailu, White Dew, is the fifteenth solar term, at the sun's longitude of 165 degrees, around the eighth of September. It is a sectional (jie) term. Its name comes from the dew that now condenses in glistening white beads on grass and leaves as the nights turn cool and the temperature swings between day and night widen. In the farming almanac it is a time of harvest and of gathering the fruits of autumn, and it is associated in some regions with the picking of tea and the making of seasonal wines. Being a solar marker, it falls near the same Gregorian date each year. These are the observances of the East Asian agricultural tradition, resting on the twenty-four-fold division of the tropical year, each term naming a precise step of the sun along the ecliptic.
Bailu, White Dew, falls at 165 degrees, around 7 or 8 September, and is a jie, or sectional, term, whose name refers to the traditional observation that overnight temperatures have cooled enough for dew to condense visibly on plants by early morning, an early and comparatively gentle sign of autumn's approach before the more marked cooling of the equinox and later terms. The term sits at the midpoint of the six terms traditionally assigned to autumn, following Liqiu and Chushu and preceding Qiufen, the autumn equinox, and in some regional customs it is associated with drinking tea, since the season's tea harvest, particularly for certain white and oolong varieties, is traditionally timed close to this point in the year.