Hi @Housear 
The Common App opens on August 1, but the time you get your decision depends on if you apply Early Decision (binding), Early Action (non-binding), or Regular Decision. If you are planning on knocking everything out soon, your best course would be to apply Early Action, which is open until November 1. Then the admissions committee gets together presumably November 2 or shortly thereafter to consider all ED and EA applications. EA decisions have typically come out during the holiday season. I think it would probably be around December 11 this year, comparing calendar dates from previous years. Similarly RD applications end on Feb 1, and decisions come out sometime in March or April.
I hope this answers your question. Let me know if you have more!