comparing nodes in xml with xslt

Hi All ,

I am transforming xml data to html page wiith the help of xslt . I want to eliminate duplicate data where appears like this in the following way .
xml data
---------


May 11
Mother's Day


May 12
Birthday


May 12
Board Meeting



My xslt code
-----------

xmlns:xsl="http://www.w3.org/1999/XSL/Transform">


 
 
 

Event Dates

 
 
 
 
 
 
 
 
 
 
 
 

date	description

 
 



My output
-------------
date    description
May 11   Mother's Day
May 12   Birthday
May 12   Board Meeting
Desired Output.
------------------
date  description
May 11
  Mother's Day

May 12
  Birthday
  Board Meeting

Please suggest me the XSLT code to modify .
Thanks in advance .