XML : How to create two date formats using XSLT

The input XML is:

  <elems>    <elem dataType="java.lang.String">N</elem>    <elem dataType="java.lang.Date"/>2015-12-29</elem>    <elem dataType="java.lang.String">      <TEST>        <TEST1>          <TEST2>            <ACT>CREATE</ACT>            <START_DATE>2015-12-19</START_DATE>            <END_DATE>2015-12-29</END_DATE>          </TEST2>          <TEST2>            <VER>1</VER>            <START_DATE>2015-12-29</START_DATE>            <END_DATE>2015-12-29</END_DATE>          </TEST2>          </TEST1>      </TEST>    </elem>  </elems>    

I need a XSLT which can transform this XML, and change the date format for P_START_DATE_ACTIVE & P_END_DATE_ACTIVE not any other dates present in the XML.

Intended output:

  <elems>    <elem dataType="java.lang.String">N</elem>    <elem dataType="java.lang.Date"/>2015-12-29</elem>    <elem dataType="java.lang.String">      <TEST>        <TEST1>          <TEST2>            <ACT>CREATE</ACT>            <START_DATE>19-DEC-2015</START_DATE>            <END_DATE>29-DEC-2015</END_DATE>          </TEST2>          <TEST2>            <VER>1</VER>            <START_DATE>19-DEC-2015</START_DATE>            <END_DATE>29-DEC-2015</END_DATE>          </TEST2>          </TEST1>      </TEST>    </elem>  </elems>