Re-date a release?

I was wondering if it were possible to re-date a release entered in launchpad to match our official code release date and version tag.

For example:

https://edge.launchpad.net/geda/stable-1.4/1.4.0

(which I just added)

Is actually our upstream version 1.4.0-20080127

http://git.gpleda.org/?p=gaf.git;a=tag;h=31ac13b194ccdecd396c0a4adfaea6e608760cd4

I feel it would confuse people less if the release dates on launchpad were to match up.

There are also our old revisions which probably don't have the right dates, since we only recently started using launchpad.

1.4.0-20080127
1.2.1-20071231
1.2.0-20070902

We haven't added development and historic releases to launchpad, since these have never been in Ubuntu / Debian, and there is no advantage in linking them up.