title: Assign array of datetime type into panda dataframe
body: <p>I have these arrays to assign into a pandata frame.</p>
  
  <pre><code>date_quote = []
  price1 = []
  price2 = []
  </code></pre>
  
  <p>The arrays have been filled with values. <code>price1[]</code>, <code>price2[]</code> contains floating  values while <code>date_quote[]</code> contains <code>datetype</code> values.</p>
  
  <p>This is how I assign the arrays into the panda dataframe.</p>
  
  <pre><code>df = pd.DataFrame({'price1 ':price1 ,
                     'price2 ': price2 ,
                     'date': date_quote
                     })
  </code></pre>
  
  <p>I get the following error;</p>
  
  <pre><code>  File "pandas\_libs\tslib.pyx", line 492, in pandas._libs.tslib.array_to_datetime
    File "pandas\_libs\tslib.pyx", line 537, in pandas._libs.tslib.array_to_datetime
  ValueError: Tz-aware datetime.datetime cannot be converted to datetime64 unless utc=True
    File "pandas\_libs\tslibs\conversion.pyx", line 178, in pandas._libs.tslibs.conversion.datetime_to_datetime64
    File "pandas\_libs\tslibs\conversion.pyx", line 387, in pandas._libs.tslibs.conversion.convert_datetime_to_tsobject
  AttributeError: 'pywintypes.datetime' object has no attribute 'nanosecond'
  </code></pre>
  
  <p>The problem comes from assigning <code>date_quote[]</code> which is <code>datetime</code> type. The code runs successfully if I do not assign <code>date_quote[]</code> into the dataframe.</p>
  
  <p>Contents of <code>date_quote[1]</code> looks like <code>2018-07-26 00:00:00+00:00</code>. I only need the date and do not need the time information in <code>date_quote[]</code>. Do I need to do any extra conversion to store this <code>datetime</code> type <code>date_quote[]</code> array into the dataframe?</p>
  
  <p>The output of <code>print (date_quote[:3])</code> is
  <code>
  [pywintypes.datetime(2018, 7, 26, 0, 0, tzinfo=TimeZoneInfo('GMT Standard Time', True)), pywintypes.datetime(2018, 7, 27, 0, 0, tzinfo=TimeZoneInfo('GMT Standard Time', True)), pywintypes.datetime(2018, 7, 30, 0, 0, tzinfo=TimeZoneInfo('GMT Standard Time', True))]
  </code></p>
  
  <p>I am using python v3.6</p>