A modified version of the suggested patch has been committed to SVN but
hasn't been uploaded yet.
Before uploading the package I'd like to understand who is going to set
the DEB_BUILD_DATE variable. It could be set by maven-debian-helper but
this would be Java specific. I think it should be set by a build tool
common to all packages instead since replacing timestamps is a common
issue (C macros  come to mind for example).
This is the maintainer address of Debian's Java team
debian-j...@lists.debian.org for discussions and questions.