I’ve dried basil 2 ways this summer - hanging from my basement ceiling on a clothesline in a room where our dehumidifier runs; took about 2 weeks. And the rest in my dehydrator; took about 2 hours per batch. :) Although spread out on the counter would probably fall somewhere in the middle, maybe a couple days? Herbs dry pretty fast in a dehydrator, and all I have is a relatively cheap one from Walmart. Once dried, I crumble it into small pieces with my hands and store in jars - that’s it, should keep for a long time that way.
Worth mentioning, from my own experience, when drying basil, try to pinch the leaves off the stem as much as possible, not so much the little leaf stem but the larger stem the leaves are attached to, because they dry into very thin sharp needle-like sticks that are hard to hand-crush.
As we all know there is NO comparison between store bought herbs and herbs dried at home. That goes for oregano, dill, basil, thyme, chives, everything but cilantro, which loses all flavor and odor when dried and must be used fresh or frozen.
On storing dried herbs...
I strongly encourage that dry herbs NOT be crushed into small pieces. By doing that, the surface area is increased and the volatiles will depart more quickly and oxidation will be faster. Store in the largest pieces you can manage to dry—crumble upon use.