how do I add extra classes to a date field at views?
You can do this without any additional modules.


Add the date field. Exclude this from the display.  Choose custom, and write d in the box (as in php date for the day).  Change the 'Style Settings' - Customize field HMTL (set to none) and  Customize field and label wrapper HTML (set to none). 
Add the date field again.  Exclude this also from the display. Choose custom, and write M in the box (as in php date for the month).  Change the 'Style Settings' - Customize field HMTL (set to none) and  Customize field and label wrapper HTML (set to none).
Add the date field again. Exclude this also from the display.  Choose custom, and write Y in the box (as in php date for the year). Change the 'Style Settings' - Customize field HMTL (set to none) and  Customize field and label wrapper HTML (set to none).
Add the date field again (LAST TIME!).  DO NOT EXCLUDE THIS FROM THE DISPLAY. Choose custom, and write G:i (as in php date for the hours and minutes). Change the 'Style Settings' - Customize field HMTL (set to none) and  Customize field and label wrapper HTML (set to none).
Rewrite the results of this final date field.  Using the replacement patterns, you can then write something like this:

&lt;div class="date"&gt;
  &lt;span class="day"&gt;
    [created]
  &lt;/span&gt;
  &lt;span class="month"&gt;
    [created_1]
  &lt;/span&gt;
  &lt;span class="year"&gt;
    [created_2]
  &lt;/span&gt;
&lt;/div&gt;