title: Swift In App Subscription How to check active status?
body: <p>This question might have been asked but I did not find a good solution for me.</p>
  
  <p>So: If I want to check if a user is subscribed in my app for a week or month, is there a specific value that says "active" true / false OR do I have to calculate it in code by checking the current timestamp with the start of subscription?</p>
  
  <p>Like: `currentDate - dateSubscribed = daysRemaining</p>
  
  <p>I saw codesampes but I could not determine it from the samples.</p>