The way you do this is very easy: set an exact time for the notification, then select whether you want it to repeat every day, every week, every hour, etc. Lastly, write the text you want the notification to include.
Once the notifications are scheduled, the application will remain minimized in the system tray. The pop-up windows emerge from here whenever your notification's time arrives.
Take Note is a very interesting tool in large part because it's so easy to manage. You can start using it in no time.