The rx:EndTime in ebay item RSS feeds is related to utime or Unix time
The numerical content is multiplied by 1000 so it has to be divided by 1000 to convert it back to utime.
Dividing the content by 1000 gives
Put this into a utime online conversion such as http://www.epochconverter.com/ and you get
GMT: Fri, 24 Feb 2012 23:12:14 GMT
The GMT end time can then be converted to your local time by the usual methods.