How to edit commit author without changing date?

Question

I already know how to change the author of the commit (author and commit field),

git rebase --root --exec "git commit --amend --reset-author --no-edit"

but with the change of the author the dates (author date and commit date) are changed as of the current date. How do I save the old dates and change the author at the same time?

Answer 1

I answer this here. In short:

git -c rebase.instructionFormat='%s%nexec GIT_COMMITTER_DATE="%cD" GIT_AUTHOR_DATE="%aD" git commit --amend --no-edit --reset-author' rebase -f <commit/branch before wrong author and email, or --root to rebase all>

Answer 2

This is not a complete solution to your question, as the commit date is still updated (this does change the commit after all), but it might be suitable for anyone that just wants to keep the author date unchanged.

Rather than using --reset-author with also updates the author date, you can just set the author explicitly.

git rebase --root --exec "git commit --amend --author=John --no-edit"

You can specify what you want as the author explicitly, or use a use a search pattern (which is what the example above does).

--author=

Override the commit author. Specify an explicit author using the standard A U Thor format. Otherwise is assumed to be a pattern and is used to search for an existing commit by that author (i.e. rev-list --all -i --author=); the commit author is then copied from the first such commit found.

Source