title: R - How to subset a dataframe by month?
body: <p>Ok so I'm trying to subset this data for the months of June, July and August respectively. I converted the dates to class "Date" by using the as.Date function. </p>
  
  <pre><code>BG.data$Date &lt;- as.Date(BG.data$TIMESTAMP, format = "%d/%m/%Y")
  </code></pre>
  
  <p>Next I try to subset the data by selecting the start and end dates in the month of July.</p>
  
  <pre><code>July &lt;- selectByDate(BG.data$Date, start = "1/7/2014", end = "31/7/2014")
  </code></pre>
  
  <p>And I keep getting this error message.</p>
  
  <pre><code> Error in as.Date.default(date) : 
   do not know how to convert 'date' to class “Date”
  </code></pre>
  
  <p>Why??!!!? I have what I'm trying to subset in the class Date so I don't know why it won't work!</p>