Seat / Saddle / Endurance

Ed wrote in :
If everything "matches up", and the appropriate callouses have
developed, how long should I be able to sit on the saddle without
*having* to get up to regain some circulation?

On flat terrain, I can sit on my saddle in one position for hours at a time
(moving my hands around, but not my rear end).

In the hills, I put more pressure on my butt at times, but I also move around
a lot more to even it out.