In order to conduct a typical sleep window set up in Garmin connect App first of all open the application then click the option “settings” then from the next menu click “user settings” then edit your “bed time” or “wake time” then touch the back button as the process comes to an end. I hope this resolves the problem of sleep window set up, for any more help or assistance connect with the Garmin Support Team & http://www.garmincustomerservice.co.uk/