Cusp-a point of transition, as from one historical period to the next; the borders between the twelve astrological signs. You are considered to be "on the cusp" if you were born within a day or two of the beginning or end of any sign.
The Rocky Mountains, Lander's Peak, 1863; Albert Bierstadt
They came bringing to him a paralytic carried by four men.
Unable to get near Jesus because of the crowd,
they opened up the roof above him.
After they had broken through,
they let down the mat on which the paralytic was lying.
When Jesus saw their faith, he said to him,
“Child, your sins are forgiven.”
James Tissot (French, 1836-1902). The Palsied Man Let Down through the Roof (Le paralytique descendu du toit), 1886-1896