From Wikpedia:
Libra is an astrological sign, which is associated with the constellation Libra, as can be seen here[1] in the Southern Hemisphere near Scorpius and Virgo. Under the tropical zodiac, Libra is occupied by the Sun from September 23 to October 23, and under the sidereal zodiac, it ends on November 15. Libra, (The Scales of Balance), is the only symbol of the zodiac that is inanimate (it is not represented by an animal or person). The opposite sign to Libra is Aries.
But hen we also have this:
Sidereal astrology is the system of astrology used by some Western and all Jyotish astrologers who base their interpretation around the use of the sidereal zodiac. It was introduced to the West by the Irish astrologer Cyril Fagan in 1944 and is practiced by a minority of Western astrologers. Its primary feature is that the signs of the zodiac align to the sky constellations of the same name. The signs therefore run between dates which are different to the tropical zodiac used in the West. For example, Aries runs from March 21 to April 20 in the tropical zodiac but extends from April 14 to May 14 in the sidereal (although the precise dates may vary depending on the sidereal system used).
But I can't tell you exact what used in MB software
