ust be given units, just as <code>time.Duration</code>
formats them: <code>10s</code>, <code>1h30m</code>, etc.
</p>

<pre><!--{{code "/doc/progs/go1.go" `/timeout/`}}
-->var timeout = flag.Duration(&#34;timeout&#34;, 30*time.Second, &#34;how long to wait for completion&#34;)</pre>

<p>
<em>Updating</em>:
Programs that implement their own flags will need minor manual fixes to update their
<code>Set</code> methods.
The <code>Duration</code> flag is new and affects no existing code.
</p>


<h3 id="go">The go/