Not contgious. Most pneumonias do not spread from person to person like head colds, there develop when bacteria living in the nose and mouth are aspirated into the lungs. There are exceptions if you have viral pneumonia or pneumonia from the flu. In those cases you could transmit it for a variable period of time until you are no longer sneezing or coughing.
Up to 10 days. It can definitely vary, but a week to 10 days is common.