As I read it, yes it appears that even just changing the last date does not make sense. For example assuming a valid 1999-2004 and the file is updated in 2006, 1999-2006 would not be correct, if I understand it, but instead 1999-2004,2006 would be "more correct"... I think :)
In any case, I reverted the 1.3-related patch and will hold off releasing 1.3.35 until this is resolved. This should be added (if not already) to next week's board meeting since it's a policy change that all projects should adhere to (the Jackrabbit method)...