XSLT - Passing params from one template to another
<xsl:variable name="date.format">%B %d, %Y</xsl:variable>
<xsl:variable name="someDate">
    <xsl:call-template name="dt:format-date-time">
        <xsl:with-param name="xsd-date-time" select="//someDate"/>
        <xsl:with-param name="format" select="$date.format"/>
    </xsl:call-template>
</xsl:variable>