title: Converting UTC to local
body: <p>My timezone is United States Eastern Standard Time which is 5 hours behind UTC. Given that:</p>
  
  <pre><code>struct tm t = { 0, 30, 15, 10, 3, 112, 0, 0, -1 };
  time_t utc_in_timet = _mkgmtime(&amp;t);
  
  struct tm tt = { 0 };
  localtime_s(&amp;tt, &amp;utc_in_timet);
  </code></pre>
  
  <p>tt is off by one hour when localtime_s returns. I have 11:30 in there instead of 10:30.</p>
  
  <p>What am I missing?</p>