one of the most popular search buttons is "New"
It searches for reservations created recently, regardless of what their rental dates are. (from & to dates)
But what do we mean by recent / New?
It defaults to 5 days. But you can customise it (per user) to something useful to the way you operate.
Click on the user menu, top right of the application.
Select the 'user settings' menu item:
You will see this:
simply change it to your new definition of new and press save.
It will be saved for your user account (not globally for the store)