I have never painted a car body with Tamiya acrylic so I may not be the best person to weigh in here, though coincidentally the model on my bench right now WILL be painted with this paint. I would think that at least two days should do it, but I tend to err on the side of caution and wait longer than the minimum recommended for any paint. I will probably wait a week before I attempt to polish it out.
Here is some solid advice though, Use Tamiya for clear instead of Future. Future was fairly popular a few years ago among the community, and I have seen some great finishes done with Future, but it has its issues. It requires developing a technique for applying it and is much less forgiving than proper hobby paint. I used it on one build and experimented extensively to learn its behaviour prior to applying it. It naturally flows out nicely, enough that most people apply it with a wide brush or even a cotton ball, though I used an airbrush. However it never stops flowing until it sets up, meaning most of the product you apply will run back off and need to be blotted with a paper towel etc. This makes the finish very thin, and since I intended to polish out the clear coat I tried applying multiple coats, but subsequent coats seem to reliquify some of the existing coat. The result was a mess that I did manage to polish out, but I found the result no better than normal hobby clears. The aggravation and the results did not justify the cost savings. I don't wish to deter your own desires to experiment with this stuff, but for a new or returning builder I will recommend against it.
I do keep some around the bench, though. It has many other uses. I use it as an adhesive for small items on the body such as PE scripts, and especially for small clear parts such as headlights, taillights, etc.