title: Perl: Undefined subroutine &main::gmdate?
body: <p>Here is what I'm trying to do (nothing complex):</p>
  
  <pre><code>use Digest::MD5 qw(md5 md5_hex md5_base64);
  
  $apikey = '1234';  
  $secret = '123';  
  $timestamp = gmdate('U');
  $sig = md5($apikey . $secret . $timestamp);
  
  echo $sig
  </code></pre>
  
  <p>So, the error occurs on the $timestamp = gmdate line. </p>
  
  <p>What am I doing wrong?</p>