title: read.csv in R reading dates differently
body: <p>I have two very similar csv files. Stock prices for 2 different stocks downloaded from the same source in the same format. However, read.csv in R is reading them differently.</p>
  
  <pre><code>&gt; tab1=read.csv(path1)
  &gt; tab2=read.csv(path2)
  
  &gt; head(tab1)
          Date   Open   High    Low  Close  Volume Adj.Close
  1 2014-12-01 158.35 162.92 157.12 157.12 2719100  156.1488
  2 2014-11-03 153.14 160.86 152.98 160.09 2243400  159.1004
  3 2014-10-01 141.16 154.44 130.60 153.77 3825900  152.0036
  4 2014-09-02 143.30 147.87 140.66 141.68 2592900  140.0525
  5 2014-08-01 140.15 145.39 138.43 144.00 2027100  142.3459
  6 2014-07-01 143.41 146.43 140.60 140.89 2131100  138.4461
  
  &gt; head(tab2)
         Date  Open  High   Low Close  Volume Adj.Close
  1 12/1/2014 73.39 75.20 71.75 72.29 1561400  71.92211
  2 11/3/2014 69.28 74.92 67.88 73.74 1421600  72.97650
  3 10/1/2014 66.18 74.95 63.42 69.21 1775400  68.49341
  4  9/2/2014 68.34 68.57 65.49 66.32 1249200  65.63333
  5  8/1/2014 67.45 68.99 65.88 68.26 1655400  67.20743
  6  7/1/2014 64.07 69.50 63.09 67.46 1733600  66.41976
  </code></pre>
  
  <p>If I try to use colClasses in read.csv then the dates for the second table are read incorrectly. </p>
  
  <pre><code>&gt; tab1=read.csv(path1,colClasses=c("Date",rep("numeric",6)))
  &gt; tab2=read.csv(path2,colClasses=c("Date",rep("numeric",6)))
  
  &gt; head(tab1)
          Date   Open   High    Low  Close  Volume Adj.Close
  1 2014-12-01 158.35 162.92 157.12 157.12 2719100  156.1488
  2 2014-11-03 153.14 160.86 152.98 160.09 2243400  159.1004
  3 2014-10-01 141.16 154.44 130.60 153.77 3825900  152.0036
  4 2014-09-02 143.30 147.87 140.66 141.68 2592900  140.0525
  5 2014-08-01 140.15 145.39 138.43 144.00 2027100  142.3459
  6 2014-07-01 143.41 146.43 140.60 140.89 2131100  138.4461
  
  &gt; head(tab2)
          Date  Open  High   Low Close  Volume Adj.Close
  1 0012-01-20 73.39 75.20 71.75 72.29 1561400  71.92211
  2 0011-03-20 69.28 74.92 67.88 73.74 1421600  72.97650
  3 0010-01-20 66.18 74.95 63.42 69.21 1775400  68.49341
  4 0009-02-20 68.34 68.57 65.49 66.32 1249200  65.63333
  5 0008-01-20 67.45 68.99 65.88 68.26 1655400  67.20743
  6 0007-01-20 64.07 69.50 63.09 67.46 1733600  66.41976
  </code></pre>
  
  <p>Not sure how I can make this issue reproducible without attaching the .csv files. I'm attaching snapshots of the two files. Any help will be appreciated. <img src="https://i.stack.imgur.com/voQfW.jpg" alt="tab1"> <img src="https://i.stack.imgur.com/k2Miu.jpg" alt="tab2"></p>
  
  <p>Thanks</p>