title: Recognizing Excel Date formatted column in .csv file as a Date for time series conversion
body: <p>I have downloaded the DJI historical data from Yahoo as a csv for further analysis in R. Out of curiosity <code>getSymbols("^DJI")</code> didn't seem to work, but I digress.</p>
  
  <p>The point is that I don't know how to turn this <code>csv</code> file into a time series format.</p>
  
  <p>Here is the output and problem so far:</p>
  
  <pre><code>&gt; DJI = read.csv("^DJI.csv")
  &gt; head(DJI)
         Date    Open    High     Low   Close Adj.Close   Volume
  1 1/29/1985 1277.72 1295.49 1266.89 1292.62   1292.62 13560000
  2 1/30/1985 1297.37 1305.10 1278.93 1287.88   1287.88 16820000
  3 1/31/1985 1283.24 1293.40 1272.64 1286.77   1286.77 14070000
  4  2/1/1985 1276.94 1286.11 1269.77 1277.72   1277.72 10980000
  5  2/4/1985 1272.08 1294.94 1268.99 1290.08   1290.08 11630000
  6  2/5/1985 1294.06 1301.13 1278.60 1285.23   1285.23 13800000
  &gt; chartSeries(DJI)
  Error in try.xts(x, error = "chartSeries requires an xtsible object") : 
    chartSeries requires an xtsible object
  </code></pre>
  
  <p>So the <code>{quantmod}</code> function <code>chartSerie</code> is requesting an <code>.xts</code> file, but the <code>Date</code> column in <code>DJI</code> is not immediately recognized as such:</p>
  
  <pre><code>&gt; DJI = as.Date(DJI$Date)
  Error in charToDate(x) : 
    character string is not in a standard unambiguous format
  </code></pre>
  
  <hr>
  
  <p>EDIT after the answer below:</p>
  
  <pre><code>&gt; head(DJI)
                Open    High     Low   Close Adj.Close   Volume
  1985-01-29 1277.72 1295.49 1266.89 1292.62   1292.62 13560000
  1985-01-30 1297.37 1305.10 1278.93 1287.88   1287.88 16820000
  1985-01-31 1283.24 1293.40 1272.64 1286.77   1286.77 14070000
  1985-02-01 1276.94 1286.11 1269.77 1277.72   1277.72 10980000
  1985-02-04 1272.08 1294.94 1268.99 1290.08   1290.08 11630000
  1985-02-05 1294.06 1301.13 1278.60 1285.23   1285.23 13800000
  &gt; is.ts(DJI)
  [1] FALSE
  </code></pre>