title: Assign default value 6 months in the past to datetime variable on data.stackexchange.com
body: <p>I found  a query on data.stackexchange.com (<a href="https://data.stackexchange.com/stackoverflow/query/4038/find-interesting-unanswered-questions" rel="nofollow noreferrer">Interesting unanswered questions</a>) and wanted to make a variation with an optional datetime variable to avoid getting questions that are very old in the results.</p>
  
  <p>I hard coded a date six months in the past <code>DECLARE @FromDate datetime = ##FromDate?2018-06-01##</code> which works okay for now, But I would like to future-proof it.</p>
  
  <p>Is it possible to assign a default date which is dynamically six months in the past in a not-too-round about way?</p>
  
  <p><a href="https://data.stackexchange.com/stackoverflow/query/969880/find-interesting-unanswered-questions-with-date-limit?FromDate=2018-06-01&amp;UserId=1725871" rel="nofollow noreferrer">Interesting unanswered questions with date limit</a></p>