docs: def milliseconds_offset(cls, timestamp, now=None):
          """ Offset time (in milliseconds) from a |datetime.datetime| object to now """
          if isinstance(timestamp, (int, float)):
              base = timestamp
          else:
              base = cls.to_unix(timestamp)
              base += (timestamp.microsecond / 1000000)
          if now is None:
              now = time.time()
          return (now - base) * 1000