title: SQL Finding the first day of the month of a data set
body: <p>I've found lots of code in getting the sql to display the first of a month, but I need to display the first day of the month based on my data set not just <code>[month] 1st [year]</code></p>
  
  <p>EX 1: January 1st is a holiday, so it'll never be the first day of the month in the data set, the first day of January is January 2nd. 
  Another example is if the first date of the month is the 7th in my data set, I want to see the 7th not the 1st.</p>
  
  <p>This is my data set</p>
  
  <pre><code>DATE
  ----------
  2016-02-01
  2016-02-05
  2016-02-08
  2016-02-19
  2016-02-20
  2016-02-22
  2016-05-02
  2016-05-05
  2016-05-07
  2016-05-09
  2016-05-11
  2016-05-23
  2016-06-01    
  2016-06-10
  2016-06-20
  2016-06-29
  2016-07-01   
  2016-07-07 
  2016-07-14 
  2016-07-21 
  2016-07-28 
  2016-07-31 
  2016-08-04 
  2016-08-10 
  2016-08-18 
  2017-02-23 
  2017-02-30 
  </code></pre>
  
  <p>I need this to display</p>
  
  <pre><code>DATE
  ----------
  2016-02-01
  2016-05-02
  2016-06-01    
  2016-07-01   
  2016-08-04 
  2017-02-23 
  </code></pre>
  
  <p>I keep getting stuck, I thought this may work but I'm not getting the min date for that month</p>
  
  <pre><code>select min(load_date) from multi_dt
  group by month(load_date)
  </code></pre>