$> git checkout --orphan master
$> git rm -rf *
$> git filter-branch --env-filter \
"if test \$GIT_COMMIT = 'e6dbcffca68e4b51887ef660e2389052193ba4f4'
then
export GIT_AUTHOR_DATE='Sat, 14 Dec 2013 12:40:00 +0000'
export GIT_COMMITTER_DATE='Sat, 14 Dec 2013 12:40:00 +0000'
fi"