Xslt 1.0 : Adding hours (integer) to time stamp

Question

I am struggeling to add 2 hours to a time stamp. It is not a possibility to upgrade to XSLT version 2.0 unformatunately.

08:40:20

Desired output:

10:40:20

Answer 1

Well, you could do simply:

<xsl:template match="Time">
    <DesiredTime>
        <xsl:value-of select="substring-before(., ':') + 2" />
        <xsl:text>:</xsl:text>
        <xsl:value-of select="substring-after(., ':')" />
    </DesiredTime>
</xsl:template> 

If you want it to roll back to 0 after midnight, then do:

         <xsl:value-of select="(substring-before(., ':') + 2) mod 24" />

and if you want a leading zero then wrap it in format-number().