title: Python- Drop hours:minutes:seconds form timedelta64[ns] data throughout the dataframe
body: <p>I have a dataframe of following format:</p>
  
  <p><a href="https://i.stack.imgur.com/3sYNC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3sYNC.png" alt="dataframe format"></a></p>
  
  <p>the last column of my dataframe is 
  <a href="https://i.stack.imgur.com/Z4DFN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Z4DFN.png" alt="last column"></a></p>
  
  <p>the hours, minutes and seconds data is completely irrelevant for my analysis work and i need to remove them.
  I found the following resources in stack-overflow but none of them seem to help.</p>
  
  <p><a href="https://stackoverflow.com/questions/45858155/removing-the-timestamp-from-a-datetime-in-pandas-dataframe">Removing the timestamp from a datetime in pandas dataframe</a></p>
  
  <p>I tried </p>
  
  <pre><code>pd.DatetimeIndex(df3).dt.date
  </code></pre>
  
  <p>but the error occurs <code>Buffer has wrong number of dimensions (expected 1, got 2)</code></p>
  
  <p>I tried dropping the H:M:S from only one column ['STDEV']</p>
  
  <pre><code>df3['STDEV']=df3['STDEV'].strftime("%m/%d/%Y")
  </code></pre>
  
  <p>but i get the error <code>'Series' object has no attribute 'strftime'</code></p>
  
  <p>I also tried using <code>apply()</code> </p>
  
  <pre><code>df3.apply(pd.to_datetime(df3)).dt.date
  </code></pre>
  
  <p>which didnt work as well</p>
  
  <p>Please let me know where i went wrong.Thanks in advance</p>