Server side include (ssi) if condition not working

Question

the if contition is to test for the day of the week:

<!--#if expr="$DATE_LOCAL = /Thursday/" -->
Thursday
<!--#endif -->

this works if the .shtml is in a static location but, not inside a war.

Yes the web.xml file has been configured correctly. as this <!--#echo var="DATE_LOCAL" --> works fine, for the .shtml page inside the war.

i am using: Apache Tomcat/5.5.9