title: Distinct year-months with Linq (to entities)
body: <p>I have an entity set of Publications with a ReleaseDate property. I would like to get a List of all distinct year-&amp;-month combos from this set for the purpose of creating a pagination widget.</p>
  
  <p>Preferably, I'd like a list of DateTime values with the day as 1 for each distinct year-month  from my publications set:</p>
  
  <pre><code>IEnumerable&lt;DateTime&gt; DistinctYearMonths = from p in context.Publications.  .... ?
  </code></pre>
  
  <p>How can I finish this linq-to-entities query?</p>