title: XSLT date-time() function is unknown in ALTOVA XmlSpy
body: <p>Good day! I downloaded Altova XMLSpy trial, installed FOP 0.95 and tried to perform XSLT (version 1.0) transformation. My template is valid but during the transformation it fails on the line containing "date-time()" function:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:fo="http://www.w3.org/1999/XSL/Format" xmlns:dt="http://exslt.org/dates-and-times" xmlns:exsl="http://exslt.org/common" extension-element-prefixes="dt exsl"&gt;
  &lt;xsl:output method="html" encoding="utf-8" indent="yes"/&gt;
  
  &lt;xsl:template match="/"&gt;
      &lt;html&gt;
          &lt;body&gt;
              &lt;xsl:value-of select="dt:date-time()"/&gt;
          &lt;/body&gt;
      &lt;/html&gt;
  &lt;/xsl:template&gt;
  
  &lt;/xsl:stylesheet&gt;
  </code></pre>
  
  <p>The error message is:</p>
  
  <pre><code>Error in XPath expression
  Unknown function - Name and number of arguments do not match any function signature in
  the static context - 'http://exslt.org/dates-and-times:date-time'
  </code></pre>
  
  <p>Please how to make this function available? I'm sure this function exists. The template works for example in this online XSLT tester: <a href="http://markbucayan.appspot.com/xslt/index.html" rel="nofollow">http://markbucayan.appspot.com/xslt/index.html</a></p>
  
  <p>Thank you in advance! Vojtech</p>
  
  <p>UPDATE: I installed SAXON 9 (both HE and EE), configured ALTOVA to use it but again the same error.</p>