Your zodiac sign may not actually be your zodiac sign anymore. (UPDATE: Scroll down for Twitter reactions -- and to submit your own!)

Astronomer Parke Kunkle says that due to changes in the Earth's alignment the dates of many zodiac signs have changed, according to NBC. In addition, there may be a 13th Zodiac sign: Ophiuchus.

Kunkle says that as the Earth and Sun slowly move the signs gradually change, as expected.

The change didn't happen overnight either. The 12 signs were designated to different periods of the year almost 3,000 years ago, when astrology began, and since then the Earth's position in relation to the sun has changed.

While the sign many people were born under may now be different, it shouldn't affect horoscope readings, according to NBC.

UPDATE: The Associated Press reported Friday evening that Kunkle has since clarified his earlier statements, emphasizing "this is not new news," and "Astronomers have known about this since about 130 B.C."

ABC News reports popular astrologer Susan Miller called the claim of new Zodiac signs "ridiculous," adding "We've known about this for ages."

The confusion seems to be a result of Eastern vs. Western astrology. Most of us are familiar with tropical zodiac (Western), based on the seasons, which has not changed, though sidereal zodiac (Eastern), based on constellations, has different signs including a 13th. Is there a correct system? That's up for debate.

See if your Zodiac sign has changed below based on the new claim. (And find out if your friends' signs have changed here or under the dates below.)

The New Dates:

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

UPDATE: See Twitter reactions below -- and submit your own!