Planning something nine weeks out? What date is 9 weeks from today comes down to one simple move. Add 63 days to today's date. That works because 9 weeks always equals 9 Γ 7 days. No month-length guessing needed.
Planning something further out? What date is 7 weeks from today comes down to one small piece of math: add 49 days to today's date. Since a week is always seven days, 7 weeks is always 49 days, no matter which month you start in. Count forward 49 days on the calendar and you land on your answer, weekday and all.
Planning something six weeks out? What date is 6 weeks from today is really just a counting question: take today's date, add 42 days, and read off the result. There is no month-guessing involved, because a week is always exactly seven days, no matter which month it crosses.
Wondering what date is 4 weeks from today? Grab a calendar and count forward 28 days from right now. Four weeks is always exactly 28 days. A week never changes length. The weekday stays the same too. Whatever day it is today, that is the weekday you land on four weeks out.