title: Flutter - Rest API Auth expiry
body: <p>I am currently implementing Auth in my Flutter app using a REST API built in .Net.</p>
  
  <p>The rest API returns a token and token expiry date, I am storing this information in Secure Storage.</p>
  
  <p>The app consists of multiple pages (Scaffold).</p>
  
  <p>My question is, how can I have a background task that watches the expiry date, and automatically logs the user out when the token is expired?</p>
  
  <p>Here is the format my date is stored in "2019-07-31T11:25:46.2265012Z"</p>