How to display on page the date as "dd-mmm-yyyy"

I am sending email by aspx and htmlbody = "<html><body>Today is 23/10/13</body></html>
In fact the date above is coming from elsewhere
I want to make it "Today is 23 Oct 2013", How should I modify the above HTML code ?
I tried
<html><body>Today is format(23/11/13,"dd-mmm-yyyy") </body></html>
it does not work