The precision used for timeout values in the Python API is inconsistent. In some case (messenger's timeout for example), timeouts are expressed in seconds using a float. In other cases, (driver wait(), etc), timeouts are expressed in milliseconds.
To be consistent with the Python time module, we should be expressing timeout values as seconds using a float.
There should be no change to the AMQP timestamp type, of course, which is defined as milliseconds since unix epoch.