A Zodiac Sign Cusp is the boundary between two adjacent Zodiac Signs in the zodiac. Each Zodiac Sign occupies a 30-degree section of the zodiac, so the transition from one Sign to the next occurs at a specific degree. In popular astrology, people born within several days of that transition are often described as being “on the cusp,” with conventions commonly ranging from about three to five days on either side. Technically, however, the Sun, Moon, Planet, or other chart factor occupies one Sign or the other according to its exact position and is not simultaneously in both Signs. Determining the correct Sign near a cusp may require the exact date, time, and location because the precise moment of transition can vary by year and time zone.