Just a side-note; I was able to select 95% of the times and days for each park on day 60 that I wanted, around 10 AM EST. Waiting until the next morning shouldn't hurt your selections. However, if you are not staying on property and you can only select at day 30, then I would probably consider staying up late to make your selections. Of course, that probably means wayyyy late as I was up over an hour-and-a-half past midnight and the system still had not released my selections by then.

Another side note, I was able to change a FP reservation at day 33 for one of my previous selections, and did not have any issues selecting what I wanted.