Pulling Data from Dates

Hey, All! I Have a quick question...

In the little chart on the left, I have the customer name, when their story is due, and when it was completed. On the right, I want to show how many words per hour my journalist is averaging for each week. What I'd like to do in cells J2 through J5 is to have a formula that pulls out the total number of words written for all projects that occurred during that time frame. I can't seem to figure out the formula, though. I was thinking that I needed an array formula starting with ifferror and calling from the row functions, but I can't seem to get it to work out right.

Can anyone help me out?

Here's my sample sheet:
sample data journalists.xlsx

Thank you so much!!!!

Pl see attached file.

Double negation to turn the True/False into a number... of course! Thank you so much!