title: Validate and select entity set data in LINQ
body: <p>I have an entity set, that contain
      name,
      id, 
      start_date 
      end_date. 
   I need to get all the records that should have start date greater than '1-1-2014' and end date should be(start date + 3 months)</p>
  
  <p>Is it possible to select that record with a single LINQ query. </p>
  
  <p>Thanks in advance.</p>