Sets the committer date to the author date for every commit in a git branch

align-commit-dates.sh

#!/bin/bash

# Get the current branch name
BRANCH=$(git rev-parse --abbrev-ref HEAD)

# Get the first commit on the current branch that is not on the main branch
FIRST_COMMIT=$(git rev-list main..${BRANCH} --reverse | head -1)

# Change the committer date to the author date for all commits from the first commit to the current branch
git filter-branch -f --env-filter 'export GIT_COMMITTER_DATE="$GIT_AUTHOR_DATE"' \
  --commit-filter 'git commit-tree -S "$@";' ${FIRST_COMMIT}^...${BRANCH}