xml - How to increment date and time in XSLT 2.0 -

i have following date scenario, in want increment in date, date format of following: 2015-05-03t00:00:00z. want increment in date of 1 day. if reaches 31 month should updated. saw existing question solution not working on scenario.

xml:

<?xml version="1.0" encoding="utf-8"?> <rootelement>      <testdate>2015-05-03t00:00:00z</testdate> </rootelement> 

xslt:

<?xml version="1.0" encoding="utf-8" ?> <xsl:transform xmlns:xsl="http://www.w3.org/1999/xsl/transform"   version="2.0">       <xsl:template match="rootelement">       <transformdate>           <xsl:value-of select="substring(testdate,1,10)" />       </transformdate>     </xsl:template> </xsl:transform> 

result:

    <?xml version="1.0" encoding="utf-8"?> <transformdate>2015-05-03</transformdate> 

expectedresult:

<?xml version="1.0" encoding="utf-8"?> <transformdate>2015-05-04t00:00:00z</transformdate> 

try stylesheet:

<?xml version="1.0" encoding="utf-8"?> <xsl:stylesheet version="2.0"     xmlns:xsl="http://www.w3.org/1999/xsl/transform"     xmlns:xs="http://www.w3.org/2001/xmlschema">      <xsl:strip-space elements="*"/>     <xsl:output indent="yes" omit-xml-declaration="yes"/>      <xsl:template match="rootelement">         <xsl:element name="transformdate">             <xsl:value-of select="xs:datetime(testdate) + xs:daytimeduration('p1d')"/>         </xsl:element>     </xsl:template>  </xsl:stylesheet>