Is the constellation calculated according to the lunar calendar or the solar calendar?

Constellations are calculated according to the solar calendar.

The twelve constellations were introduced into China from the west, belonging to western culture, and are calculated by the solar calendar (the internationally recognized Gregorian calendar). If it is according to the lunar calendar, it is the "twelve stars" of China. China native culture "Zodiac" is calculated according to the lunar calendar, also called lunar calendar.

The sun sign is the most frequently mentioned in astrology. As long as you know a person's date of birth, you can find out his sun sign. The orbit of the sun is called the ecliptic, and it is divided into 12 zones, each of which is 30 degrees. These 12 regions are what we call solar constellations. The twelve constellations begin in spring, that is, when the sun runs to the vernal equinox around March 20 every year, they will be sorted in order: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces.