git cherry-pick timestamping issue

So my first attempt at using git cherry-pick didn't go so well.
The commit in master looks like

commit ee63981c1fe26299162b9c7f1218d7e3ef802409
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date:   Thu Sep 23 15:34:56 2010 -0400
   Avoid sharing subpath list structure when flattening nested AppendRels.   
which is the correct timestamp, but all the back-patched ones look like

commit 4e60212ab5a956bcba89cfd465f945a9c8969f27
Author: Tom Lane <tgl@sss.pgh.pa.us>
Date:   Thu Sep 23 19:34:56 2010 -0400
   Avoid sharing subpath list structure when flattening nested AppendRels.

Apparently somebody's confused between local and GMT time somewhere in
there.

This is with a vanilla build of 1.7.2.3.  Anybody else see this type
of symptom?
        regards, tom lane