title: How to replace numeric dates with month names for a column in R
body: <p>I have a current DataFrame that looks like this:</p>
  
  <pre><code>      DATETIME MEAS_AVG TARG_MIN TARG_AVG TARG_MAX DESPORT_NOTE
  1  2012/04/10 14:03:37   0.2888     0.22     0.25     0.27      GOOD_PT
  2  2012/03/30 07:48:17   0.2544     0.22     0.25     0.27      GOOD_PT
  3  2012/03/24 19:23:08   0.2333     0.22     0.25     0.27      GOOD_PT
  4  2012/03/25 16:10:17   0.2111     0.22     0.25     0.27      GOOD_PT
  5  2012/04/10 00:58:29   0.2222     0.22     0.25     0.27      GOOD_PT
  6  2012/04/14 18:32:52   0.2888     0.22     0.25     0.27      GOOD_PT
  7  2012/04/21 14:47:47   0.2777     0.22     0.25     0.27      GOOD_PT
  </code></pre>
  
  <p>The data frame is called <code>df3</code> and the specific column I am looking to replace the dates for are <code>df3$DATETIME</code>.</p>
  
  <p>I have this function in my code already in order to strip the datetime:</p>
  
  <pre><code>date &lt;- strptime(df3$DATETIME, "%Y/%m/%d %H:%M:%S")
  </code></pre>
  
  <p>All I am looking to replace all the datetime information with simple month names. This is what it should look like after the replace function:</p>
  
  <pre><code>      DATETIME MEAS_AVG TARG_MIN TARG_AVG TARG_MAX DESPORT_NOTE
  1  April   0.2888     0.22     0.25     0.27      GOOD_PT
  2  March   0.2544     0.22     0.25     0.27      GOOD_PT
  3  March   0.2333     0.22     0.25     0.27      GOOD_PT
  4  March   0.2111     0.22     0.25     0.27      GOOD_PT
  5  April   0.2222     0.22     0.25     0.27      GOOD_PT
  6  April   0.2888     0.22     0.25     0.27      GOOD_PT
  7  April   0.2777     0.22     0.25     0.27      GOOD_PT
  </code></pre>
  
  <p>I am been looking all over for a simple replace column function, but can't seem to find it. I know that I can use the <code>as.Date()</code> function with the formated <code>%B</code> to return the unabreviated month. The only problem is I do not know how to use this to replace the column values already existing.</p>
  
  <p>I can list the months using this function:</p>
  
  <pre><code>list(month=months(as.Date(df3$DATETIME)))
  </code></pre>