git rebase -i without altering the committer date

I'd like to insert a commit between two commits without changing the committer date or author date of that commit or the subsequent commits. I'd planned on using `git rebase -i` to insert the commit. I believe it retains the author date, but changes the committer date to the current time. I've seen the options `--committer-date-is-author-date` and `--ignore-date`, but I don't believe either of those options does what I want. If no such option currently exists to leave the committer and author date unchanged, is there any chance that this functionality could please be implemented?

For a relevant SO question, see How to make a git rebase and keep the commit timestamp? http://stackoverflow.com/questions/30790645/how-to-make-a-git-rebase-and-keep-the-commit-timestamp

Thanks, Shaun