title: Is Firestore charging us when offline more than 30 minutes?
body: <p>I read this <a href="https://stackoverflow.com/questions/50687232/am-i-charged-with-read-operations-everytime-the-location-is-changed">answer</a>, where Doug Stevenson (Firebase engineer) said:</p>
  
  <blockquote>
    <p>Cached document reads are not charged.</p>
  </blockquote>
  
  <p>But I read in the <a href="https://firebase.google.com/docs/firestore/pricing#pricing_overview" rel="noreferrer">docs</a>:</p>
  
  <blockquote>
    <p>Also, if the listener is disconnected for more than 30 minutes (for example, if the user goes offline), you will be charged for reads as if you had issued a brand-new query.</p>
  </blockquote>
  
  <p>So if I'm going offline, even if I haven't changed any document, am I charged again? So the data that is already cached, isn't consider a cached data after 30 minutes anymore?</p>
  
  <p>Hope someone can help me about this annoying situation. Thanks in advance!</p>