title: How to test if passed in datetime (GMT) is within 5 minutes of time?
body: <p>In my service endpoint, I get a string representation of a GMT time.</p>
  
  <p>I have to validate that the passed in time is within 5 minutes of the current time.</p>
  
  <p>How should I be doing this?</p>
  
  <pre><code>        bool result = false;
          DateTime gmt;
          if (DateTime.TryParse(passedInGmtAsString, out gmt))
          {
              DateTime utcNow = DateTime.UtcNow;
  
              result  = ??
          }
  </code></pre>