My hair is naturally curly but it still takes me 2 hours to get it to a publically acceptable standard.
Of course, I'm including the shower (~40 min), putting in product (~5 min), plopping (~15-30 min, depending on how much time I have), letting it finish drying (45min to an hour), and then deciding if it curled well enough to leave down or if I need to put it up somehow ( ~0-30 min, depending).
This process could take much, much longer for someone who doesn't have natural curls.