title: How to format a Date as "YYYY-Mon" with Lubridate?
body: <p>I would like to create a vector of dates between two specified moments in time with step 1 month, as described in this thread (<a href="https://stackoverflow.com/q/14450384/4518857">Create a Vector of All Days Between Two Dates</a>), to be then converted into factors for data visualization.</p>
  
  <p>However, I'd like to have the dates in the YYYY-Mon, ie. 2010-Feb, format. But so far I managed only to have the dates in the standard format 2010-02-01, using a code like this:</p>
  
  <pre><code>require(lubridate)
  first &lt;- ymd_hms("2010-02-07 15:00:00 UTC")
  start &lt;- ymd(floor_date(first, unit="month"))
  
  last &lt;- ymd_hms("2017-10-29 20:00:00 UTC")
  end &lt;- ymd(ceiling_date(last, unit="month"))
  
  &gt; start
  [1] "2010-02-01"
  
  &gt; end
  [1] "2017-11-01"
  </code></pre>
  
  <p>How can I change the format to YYYY-Mon?</p>