It was in the afternoon just before sunset at 20 Steiner St SF CA I saw above me and there was one other person who was with me on the same back porch a very bright light hovering above us. It felt as if we were being observed, at first I thought it was a star, but it didn't twinkle or flicker. Then after watching it for a few minutes and commenting on it, it began to move in what was a zig zag pattern upward in to the sky and then all of a sudden it disappeared and what was left as it disappeared was a silowette of a oval like shape as a faint outline before it completey dissappeared from site. It moves very fast in a ziz zag pattern or zzzzzz pattern. The color was a white light.