title: Rounding dates to first day of the month
body: <p>I am using SQL Server 2014 and I am working with a column from one of my tables, which list arrival dates.</p>
  
  <p>It is in the following format:</p>
  
  <pre><code>ArrivalDate
  2015-10-17 00:00:00.000
  2015-12-03 00:00:00.000
  </code></pre>
  
  <p>I am writing a query that would pull data from the above table, including the ArrivalDate column. However, I will need to convert the dates so that they become the first day of their respective months.</p>
  
  <p>In other words, my query should output the above example as follows:</p>
  
  <pre><code>2015-10-01 00:00:00.000
  2015-12-01 00:00:00.000
  </code></pre>
  
  <p>I need this so that I can create a relationship with my Date Table in my PowerPivot model.</p>
  
  <p>I've tried this syntax but it is not meeting my requirements:</p>
  
  <pre><code>CONVERT(CHAR(4),[ArrivalDate], 100) + CONVERT(CHAR(4), [ArrivalDate], 120) AS [MTH2]
  </code></pre>