August 15th is the deadline for the materials and they won't be accepted after then, so as long as your PT sends it in before then you should be fine. That being said, if you are applying early decision it is probably best to get your materials in as soon as you can. Schools will start looking at your materials as soon as all of your material is submitted. I am applying ED to Duke, and I know they start looking at applications right away, even for ED.