这是一个演示如何在XSLT 2.0中做到这一点： p>

Here is a demonstration how to do this in XSLT 2.0:

<xsl:stylesheet version="2.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
 xmlns:xs="http://www.w3.org/2001/XMLSchema">
 <xsl:output method="text"/>

 <xsl:template match="/">
  <xsl:variable name="vToday" select="current-date()"/>

  Today is: <xsl:sequence select="$vToday"/>
  30 days ago it was: <xsl:sequence select=
    "$vToday -30*xs:dayTimeDuration('P1D')"/>
  365 days ago it was: <xsl:sequence select=
    "$vToday -365*xs:dayTimeDuration('P1D')"/>
 </xsl:template>
</xsl:stylesheet>

结果生成：

when this transformation is applied on any XML document (not used), the wanted, correct result is produced:

  Today is: 2010-10-07-07:00
  30 days ago it was: 2010-09-07-07:00
  365 days ago it was: 2009-10-07-07:00