Why does it take 16 days from the White Dew to the Autumnal Equinox in 2017?

The White Dew Time in 2017: September 7, 18:38:34, the 17th day of the seventh lunar month in 2017.

Autumn Equinox time: September 23, 04:01:44, the fourth day of August (big) in 2017 in the lunar calendar. Because the autumnal equinox is September 23 at 04:01:44, it takes up one day. So, it's 16 days.

As the name suggests, Bailu means that there is dew in this solar term. It also means that in autumn, people can clearly feel the temperature drop and the weather has turned cooler.

What does white dew mean?

The weather turns cooler and the dew condenses and turns white.

When the dew is white, fighting refers to Gui. The ecliptic longitude of the sun is 165°. As the weather gets cooler, the moisture on the ground will condense the most.

The Three Marquises of Bailu

Hongyan is coming: The bird flies from north to south, the big one is called Hong, and the small one is called Yan.

The black bird returns: Swallows and other migratory birds fly south to avoid the cold.

The birds are shy: Birds begin to store dried fruits and grains for winter.