When I use  <%# Session("copyrightDate") %> on my master page I dont get an error but it does not display anything

When I use  <% Response.Write(Session("copyrightDate"))%> on a .aspx page I dont get an error but it does display the date, but I dont want it on a .aspx page that uses the master...I want it to go in the footer of the master page

This is how i delcared the session in the page load event of the master page

'''''' Current date and time.
        Dim currDate As Date = Now

''''''Get only the year of the date
     Session("copyrightDate") = DatePart(DateInterval.Year, currDate)