I have values in the xsl:variable with name of toDate, dateFro & numDays. Variables are not possible to calculate.
Is it any option to convert to number or any adive.?

I need to do calculation such as

Reuslt = <xsl:value-of select="($toDate-$dateFro) div $numDays"/>

a) Are you getting an error? If so what is it?
b) What version of XSLT are you using?
c) I can't see anything wrong with what you've written, so if you are getting an error then it must be in the code you haven't shown us.

/- Sam Judson : Wrox Technical Editor -/

If I remember rightly elayaraja is still using XSLT 1.0 despite the fact that he/she is trying to do many things that are much easier in XSLT 2.0.

If you're stuck with 1.0 and need to do date arithmetic then the best bet (other than moving to XSLT 2.0) is to use the library of routines at http://www.exslt.org/

Michael Kay
http://www.saxonica.com/
Author, XSLT 2.0 and XPath 2.0 Programmer's Reference

Michael.Thanks for your reply with lib link.
I would like to share with you, that at this moment i can't move forward to XSL2.0.
[u]XSLT:</u> Version 1.0
[u]Processor:</u> Xalan-C_1_8_0-windows_2000-msvc_60 /xerces-c_2_5_0-windows_nt-msvc_60
[u]Platform: </u>Windows XP