title: Haskell date parsing and formatting
body: <p>I've been working with Haskell's Date.Time modules to parse a date like <code>12-4-1999</code> or <code>1-31-1999</code>.  I tried: </p>
  
  <pre><code>parseDay :: String -&gt; Day
  parseDay s = readTime defaultTimeLocale "%m%d%Y" s
  </code></pre>
  
  <p>And I think it wants my months and days to have exactly two digits instead of 1 or 2...</p>
  
  <p>What's the proper way to do this?</p>
  
  <p>Also, I'd like to print out my Day in this format: <code>12/4/1999</code> what's the Haskell way to?</p>
  
  <p>Thanks for the help.</p>