International Women's Day first emerged from the activities of labour movements at the turn of the twentieth century in North America and across Europe. Since those early years, International Women's Day has assumed a new global dimension for women in developed and developing countries alike.
The shadowed portion is entirely hidden from view. The first quarter and third quarter moons (both often called a half moon), happen when the moon is at a 90 degree angle with respect to the earth and sun. So we are seeing exactly half of the moon illuminated and half in shadow.
The umbra (Latin for shadow) is the innermost and darkest part of a shadow, where the light source is completely blocked by the occluding body. An observer in the umbra experiences a total eclipse. The umbra of a round body occluding a round light source forms a right circular cone; to a viewer at the cone's apex, the two bodies are equal in apparent size. The distance from the Moon to the apex of its umbra is roughly equal to that between the Moon and Earth.