title: is it possible to Sum values grouped by month?
body: <p>I have an SQL Server table structured as follows :</p>
  
  <pre><code>Table name : calendar. 
  </code></pre>
  
  <p>Columns : </p>
  
  <pre><code>Calendar Date (smalldatetime)
  Working Day (bit)
  </code></pre>
  
  <p>Calendar date has all dates, structured in the format yyyy-mm-dd.
  Working day means that I have work if it is a 1, and if it is a weekend or a holiday it is marked as a 0. </p>
  
  <p>What I want to retrieve :</p>
  
  <pre><code>Month      No Working Days   Year
  ------------------------------------
  January    22                2011
  February   20                2011
  March      22                2011
  ...
  December   10                2011
  January    15                2012
  </code></pre>
  
  <p>All of the information is there, but I am just not sure how to write a query like this, but I assume it would be structured something similar to this with some fancy datetime functions thrown in. Does</p>
  
  <pre><code>SELECT Sum(Working Day)
         GROUP BY (Not a clue)
  </code></pre>