This is a way of getting 4th + FP day of, at a relatively close time, that seems to work almost like magic.
You start by searching for the FP you want in the app. When you find it, basically for any time, no matter how late in the day, you take it. Once you have it, you go to that FP, and try to modify the time, then you just keep on tapping on time slots closer to the current time than the FP you currently have, until a better time pops up, which you then take, and then repeat the process. It is amazing how often you can wind up getting FP even for very popular rides like FoP, within say half an hour or 45 minutes of the current time. It is even more amazing that often enough, you can score FP like that for 15 minutes from the current time, and sometimes even closer to the current time than that.
It does require some persistence to make it work. Having 2, or even 3 people searching at the same time can help, and keeping at it, even when nothing is showing up is a big key. Often, as soon as we tap into our last FP, we will start searching for the next one, even while still walking through the queue for the current ride. Many times, between the tapstyle, and the loading area, I have already managed to line up the next FP.