title: Plotting tibble using R dygraphs
body: <p>I'm trying to plot some time-series data in R using the dygraphs package (I'm an R newbie), but having trouble and I suspect it's due to data format issues.</p>
  
  <p>Here is a sample of my code:</p>
  
  <pre><code>df &lt;- select(sal_data,DateTime,'Sal psu')
  head(df)
  typeof(df)
  class(df)
  </code></pre>
  
  <p>outputs:</p>
  
  <pre><code>DateTime
  &lt;S3: POSIXct&gt;
  Sal psu
  &lt;dbl&gt;
  2018-05-03 14:30:01 24.93           
  2018-05-03 14:45:01 24.94           
  2018-05-03 15:00:01 24.90           
  2018-05-03 15:15:01 24.89           
  2018-05-03 15:30:01 24.94           
  2018-05-03 15:45:01 24.87   
  </code></pre>
  
  <p>and</p>
  
  <pre><code>[1] "list"
  [1] "tbl_df"     "tbl"        "data.frame"
  </code></pre>
  
  <p>but when I try to do <code>dygraph(as.xts(df))</code> I get:</p>
  
  <pre><code>Error in as.POSIXlt.character(x, tz, ...) : character string is not in a standard unambiguous format
  </code></pre>
  
  <p>Any thoughts?  This seems like a simple fix but my searching hasn't found anything.
  Thanks!</p>