I have the need to figure out by week what was modified in my file system.
Fortunately there’s a string to put in the search box that will give you just that:

modified:7/2/2018 .. 7/31/2018

How about if you need to screen all emails from one week in time in Outlook.
Fortunately there’s a string to put in the search box that will give you just that:

received:7/2/2018 .. 7/31/2018

I’m sure that this format can be used in many other cases (e.g sent items) so it’s good to keep in mind.