dateTime to Epoch and vice versa xslt

Question

I have been trying to convert a given dateTime to epoch time and also a given epoch time to dateTime. I am quite new to xslt and have been struggling with this quite for som

Answer 1

To convert Unix time to ISO 8601 date-time:

<xsl:value-of select="xs:dateTime('1970-01-01T00:00:00') + xs:dayTimeDuration(concat('PT', UnixTime, 'S'))"/>

To convert ISO 8601 date-time to Unix time;

<xsl:value-of select="floor((xs:dateTime(ISODateTime) - xs:dateTime('1970-01-01T00:00:00')) div xs:dayTimeDuration('PT1S')) "/>

Requires XSLT 2.0.

Working demo: http://xsltransform.net/94rmq5L

Answer 2

If you are trying to do this in XSLT 1.0 on MSXML (I know the original asker is not):

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0" xmlns:ms="urn:schemas-microsoft-com:xslt" xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:userCSharp="http://stackoverflow.com/xsltexample">
  <xsl:output method="xml" omit-xml-declaration="yes" indent="yes" />
  <xsl:template match="/">
    <xsl:value-of select="userCSharp:DateToEpoch('1970-01-02')" />
  </xsl:template>
  <msxsl:script language="CSharp" implements-prefix="userCSharp"><![CDATA[
     public string DateToEpoch(string s)
     {
         DateTime dt = DateTime.Parse(s);  
         DateTime epoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);

         return (dt - epoch).TotalSeconds.ToString();
     }
   ]]></msxsl:script>
</xsl:stylesheet>

Replace the '1970-01-02' with whatever text node you want and this should work, as long as that node was a valid date time. If not, it's easy enough to write up another simple method to do that using DateTime.Parse/TryParse. The output of this template (against any valid XML) would be 86400. Note that it's best to define methods in a CDATA node to avoid needing to escape quotes or angle brackets (this code doesn't happen to use any but might be extended to for some reason).