If your on aas the deloading would be when ever you feel you need it. But for natty I say anywhere from 3-5 wks for loading and 1Wk too 2wks max for deloading. In my training I like to take 1off or down wk every 5-6wks. But some training cycles have then build into the system... Like 5-3-1 would be 3wks up 1wks down then a max wk, then start over. Where as somethin like smolov is set up for your failure for 13wks witchever comes first, with no down time. < with this 1 you for sure need to be on aas to even think of tryin it out. Even then it's very hard on your body and you might not be able to keep you with the number and weights set up for you.
3-5wks then a down wk... Or when over you feel you need it.