strftime: from where the locale (en, es...) is retrieved?
<p>I have just found out the function <code>strftime()</code>. The manual says about it:</p>

<blockquote>
  <p>Format a local time/date according to locale settings".</p>
</blockquote>

<p>But...from where the locale (en, es...) is retrieved?</p>
