The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on February. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
The average time it takes to obtain a patent from the patent office at this time is about 32 months or a little under 3 years. [See the current wait time statistics at the USPTO website [ here ] (best viewed with Internet Explorer)].
Certified mail generally takes as long as it takes for the receiver to be present to sign for it. In your case, I would say about three days, but again someone must be at the location for delivery to sign for it. The mailman will try to deliver it a couple of times, and then it will end up back at the post office for you to pick up there.