What constellation is the person born on the seventh day of the ninth lunar month?

The constellation is looking at the solar calendar. The solar calendar corresponding to the seventh day of the ninth lunar month in the year when you were born is your constellation.

Libra 1/2 1 ~ 2/ 18 Leo July 23rd to August 23rd.

Pisces 2/ 19 ~ 3/20 Virgo 8/24 ~ 9/22

Aries 3/2 1 ~ 4/20 Libra 9/23 ~ 10/23

Taurus 4/2 1 ~ 5/2 1 Scorpio10/24 ~1/22.

Gemini 5/22 ~ 6/2 1 Sagittarius11/23 ~121

Cancer 6/22 ~ 7/22 Capricorn 12/22 ~ 1/20