I recently needed to apply 16 patches to my repo, using \'git am\', and I was careful to use \'--committer-date-is-author-date\' for each one. However, I also needed to adjust
The value of $GIT_AUTHOR_DATE contains spaces, so you have to quote it (-0500 is your time zone offset):
$GIT_AUTHOR_DATE
-0500
git filter-branch --env-filter \ 'export GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"' SHA1..HEAD