git filter-branch --env-filter \
'if [ $GIT_COMMIT = 119f9ecf58069b265ab22f1f97d2b648faf932e0 ]
then
export GIT_AUTHOR_DATE="Fri Jan 2 21:38:53 2009 -0800"
export GIT_COMMITTER_DATE="Sat May 19 01:01:01 2007 -0700"
fi'