This repo demonstrates Viewing missing commit details from commits in your timeline in GitHub Docs.
See Git Docs
set "GIT_AUTHOR_NAME=octocat"
set "GIT_AUTHOR_EMAIL=[email protected]"
set "GIT_AUTHOR_DATE=Tue, 03 Apr 2018 02:02:30 +0900"
set "GIT_COMMITTER_NAME=Sally Johnson"
set "GIT_COMMITTER_EMAIL=USER_EMAIL"
set "GIT_COMMITTER_DATE=Tue, 10 Apr 2018 06:25:08 +0900"
git commit -m init --reset-author
git tag YOUR_COMMIT_SHA_NUMBER HEAD
git show YOUR_COMMIT_SHA_NUMBER --pretty=fuller