I used to deload when my progress stucks for 3, 4 or more weeks. It got me stressed a lot because all of that effort without any gains.
Now I am having a more conservative approach, try to deload when I feel like it is a good time to do it, even if I think I could push a little more. Sometimes it is hard to convince oneself not to go all-out everytime.
As for rest periods, I donīt plan them either. Life brings them naturally (trips, illness, social compromises, etc.)