title: Get the current year on the commandline
body: <p>Using wget, I need to download a file whose URL contains the year. How can I embed the current 4-digit year (at the time of running the command, e.g. 2015)? For example, what would the command <code>currentyear</code> be in</p>
  
  <pre><code>wget "http://example.com/data-$(currentyear).txt"
  </code></pre>
  
  <p>What would be the corresponding command if I'd need the two-digit year (e.g. 15 for 2015)?</p>