See the ExpirationPolicy.
Thanks for your reply.
I did want to mention something that might get a different answer to my original question: We are using JBoss 4.2.2GA application server and using JBoss Cache with Seam. Now, I read somewhere that JBoss Cache 2.x is not fully tested on JBoss 4.x series application servers but we need to use JBoss Cache 1.x series instead. JBoss 4.2.2 GA comes bundled with JBoss Cache 1.4.1 SP3. We can use that if that will work. Concern is that JBoss Cache 1.4.x does not provide an eviction policy out of the box that will expire values at a given time of the day.