I quess we have 13 zodiac signs not 12 , so its could be wrong. the angle of inclination of our planet is rotting & the Ophiuchus sign completely includes in the meridian .
Capricorn: Jan. 20 to Feb. 16

Aquarius: Feb. 16 to March 11

Pisces: March 11 to April 18

Aries: April 18 to May 13

Taurus: May 13 to June 21

Gemini: June 21 to July 20

Cancer: July 20 to Aug. 10

Leo: Aug. 10 to Sept. 16

Virgo: Sept. 16 to Oct. 30

Libra: Oct. 30 to Nov. 23

Scorpio: Nov. 23 to Nov. 29

Ophiuchus: Nov. 29 to Dec. 17

Sagittarius: Dec. 17 to Jan. 20