I'm trying to restrict my NHibernate query with some basic date/time manipulation. More specifically, I want to execute the following statement (pseudo-SQL):

select * from article where created_on + lifespan >= sysdate

with:

• created_on is mapped to a property of type DateTime.
• lifespan is mapped to a property of type TimeSpan.
• sysdate is the current date/time (of the database server or ofthe application host, I don't care)

Is there any built-in way to do that by using the Criteria-API or HQL?

return session
  .CreateCriteria<Article>()
  .Add( ? )
  .List<Article>();