title: strptime not recognizing %b/%B?
body: <p>I'm trying to convert some dates in R with strptime.  I've read <a href="https://stackoverflow.com/questions/13726894/strptime-in-r-works-then-stops-working-and-then-works-again">this thread</a> and have set my locale so that it should work.  For example:</p>
  
  <pre><code>&gt; Sys.getlocale("LC_TIME")
  [1] "en_GB"
  &gt; format(Sys.time(), format="%B")
  [1] "November"
  </code></pre>
  
  <p>However if I try to convert a month string, strptime returns NA, e.g.:</p>
  
  <pre><code>&gt; strptime("November", format="%B")
  [1] NA
  </code></pre>
  
  <p>I can run the example at the above link without any problem but if I simplify the example to just include the month, I get NA again.</p>
  
  <pre><code>&gt; var &lt;- "Thu Nov 8 15:41:45 2012"
  &gt; strptime(var, format="%a %b %d %H:%M:%S %Y")
  [1] "2012-11-08 15:41:45 GMT"
  &gt; strptime("Nov", format="%b")
  [1] NA
  </code></pre>
  
  <p>What's going on here?  How can I parse a character month into a date object?</p>
  
  <p><strong>EDIT</strong> 
  Thanks for the comments below.  To clarify, this also doesn't work:</p>
  
  <pre><code>&gt; strptime("November 2011", format="%B %Y")
  [1] NA
  </code></pre>
  
  <p>I would also expect <code>strptime</code> to fill in any missing fields with the current system time, as in <code>strptime("2011", format="%Y")</code></p>