title: Daylight saving time and time zone best practices
body: <p>I am hoping to make this question and the answers to it the definitive guide to dealing with daylight saving time, in particular for dealing with the actual change overs. </p>
  
  <p><strong>If you have anything to add, please do</strong></p>
  
  <p>Many systems are dependent on keeping accurate time, the problem is with changes to time due to daylight savings - moving the clock forward or backwards.</p>
  
  <p>For instance, one has business rules in an order taking system that depend on the time of the order - if the clock changes, the rules might not be as clear. How should the time of the order be persisted? There are of course an endless number of scenarios - this one is simply an illustrative one.</p>
  
  <ul>
  <li>How have you dealt with the daylight saving issue? </li>
  <li>What assumptions are part of your solution? (looking for context here)</li>
  </ul>
  
  <p>As important, if not more so:</p>
  
  <ul>
  <li>What did you try that did not work? </li>
  <li>Why did it not work?</li>
  </ul>
  
  <p>I would be interested in programming, OS, data persistence and other pertinent aspects of the issue.</p>
  
  <p>General answers are great, but I would also like to see details especially if they are only available on one platform.</p>