title: Convert date field to Quarter in R
body: <p>I have data frame which has the date column in format <code>08/21/2000(m/d/Y)</code>.</p>
  
  <p>Now I want to add new column which display the date in <strong>Quarter</strong> format that is <code>2000-Q3</code>.</p>
  
  <p>I install <em>zoo</em> package and used following command. but it is giving <code>NA</code> value. </p>
  
  <pre><code>library(zoo)
  mydf$var9=as.yearqtr("mydf$Order.Date","%m/%d/%Y").
  </code></pre>