title: How the function changeMessageVisibility of sqs message extends the visibility time?
body: <p>In its documentation of ChangeMessageVisibility function, Amazon gives the following example:</p>
  
  <blockquote>
    <p>For example, you have a message with a visibility timeout of 5
    minutes. After 3 minutes, you call ChangeMessageVisibility with a
    timeout of 10 minutes. You can continue to call
    ChangeMessageVisibility to extend the visibility timeout to the
    maximum allowed time. If you try to extend the visibility timeout
    beyond the maximum, your request is rejected.</p>
  </blockquote>
  
  <p><a href="https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_ChangeMessageVisibility.html" rel="noreferrer">https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_ChangeMessageVisibility.html</a></p>
  
  <p><a href="https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/examples-sqs-visibility-timeout.html" rel="noreferrer">https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/examples-sqs-visibility-timeout.html</a></p>
  
  <p>so, after I change the visibility time of msg to 10 minutes,
  it has 10 minutes, 12 minutes or 8 minutes left?</p>