Vacuum in the manifold drops as engine demand increases. If you use ported vacuum you always have a vacuum signal. If you want to make adjustments it can be done using the advance pot on the distributor when you use ported vacuum.
The decreasing or waning phases are when the moon shrinks from the full moon down to the new moon (darkness). As the moon wanes during the 3rd and 4th quarters, this is a good time to prune plants, as the water table is diminishing and so less sap will flow out of the cut ends.
the full moon occurs every 29 53058 days new moon a new moon occurs when the moon is between the earth and the sun we are seeing the oposite side of the moon that the sun is shinning on at the exact time of the new moon the moon is to close to the sun to see at all