It goes by months.........but sometimes to dates change. For example my mom's b-day is oct 23rd which would make her either a libra or scorpio sometimes. Here's a list of the months and how it all goes:
Aries (March 21 — April 20)
Taurus (April 21 — May 20)
Gemini (May 21 — June 21)
Cancer (June 22 — July 22)
Leo (July 23 — Aug. 22)
Virgo (Aug. 23 — Sept. 22)
Libra (Sept. 23 — Oct. 23)
Scorpio (Oct. 24 — Nov. 22)
Sagittarius (Nov. 23 — Dec. 21)
Capricorn (Dec. 22 — Jan. 20)
Aquarius (Jan. 21 — Feb. 19)
Pisces (Feb. 20 — March 20)
Somtimes these dates change a day or two. Find what date your birthday falls under and that is your Zodiac Sign. My b-day is August 8th which would make me a Leo. Now that I think about it, I don't think Ejaz is a leo cause his b-day is on the 28th which would make him a Virgo. Oh well, his b-day is still the same month as mine.
Hope I helped and answered your question!😃