I think this tool is for creating a printout or Web page of the work assignments that you will teach for the week. Not necessarily the time period.
It is something you can definitely do in other ways but this program is very lightweight and simple.
So for example;

Math:
1/7 - Simple fractions
1/8 - Integers
1/9 - Systems of Equations
Etc..
You can add more info to each line as the summary for the lesson.
Hope this helps.