title: How to parse "91212" as "Hmmss" in c#?
body: <p>The code:</p>
  
  <pre><code>var str = "91212";
  DateTime.ParseExact(str, "Hmmss", System.Globalization.CultureInfo.CurrentCulture);
  </code></pre>
  
  <p>The error:</p>
  
  <pre><code>"91212" is not a valid DateTime
  </code></pre>
  
  <p>It seems c# try to use <code>H</code> to match <code>91</code>, which is incorrect hour.</p>
  
  <p>How to fix it?</p>