That means if you were a "Leo" born in early August, you may now be a Cancer. But not all astrologers agree with the revised calendar.
The changes may have also re-introduced an old sign, Ophiuchus which was dropped by the Babylonians thousands of years ago.
Here's a list of the 'New' dates. See if your Zodiac sign changed:
Capricorn: Jan. 20 - Feb. 16
Aquarius: Feb. 16 - March 11
Pisces: March 11 - April 18
Aries: April 18 - May 13
Taurus: May 13 - June 21
Gemini: June 21 - July 20
Cancer: July 20 - Aug. 10
Leo: Aug. 10 - Sept. 16
Virgo: Sept. 16 - Oct. 30
Libra: Oct. 30 - Nov. 23
Scorpio: Nov. 23 - Nov. 29
Ophiuchus: Nov. 29 - Dec. 17
Sagittarius: Dec. 17 - Jan. 20