Cusps

Cusps. A cusp is a dividing line in the chart, the boundary where one house or sign ends and the next begins. The most important cusps are the house cusps, the twelve lines that mark where each house starts. The cusp of the first house is the Ascendant and the cusp of the tenth is the Midheaven, two of the chart's four main angles. The sign sitting on a house cusp colors the whole house, describing the style a person brings to that area of life. Because the houses are built from the exact time and place of birth, the cusps shift quickly through the day, which is part of why an accurate birth time matters. A planet placed close to a house cusp can take on the flavor of both the house it sits in and the one just ahead. The word is also used for the boundary between two signs. People born close to a sign change are sometimes said to be born on the cusp, though in practice a planet is always fully in one sign or the other, never in two at once. Cusps are simply the lines that carve the continuous circle of the chart into its meaningful divisions.