Git
work in progressAltering Commit Dates
$ (export GIT_COMMITTER_DATE="1970-01-01 00:00:00"; \
git commit --amend --date="$GIT_COMMITTER_DATE")
(The parentheses spawn a subshell, which is required for the environment variable to take effect.)
$ git log --format="%h [%cd] %ad %s"
This reveals both commit and authoring dates.
Worktree
Reifies a branch in a separate directory, without a separate repository clone:
$ git worktree add "$directory" "$branch"
$ git worktree remove "$directory"
Orphan Branches
$ git symbolic-ref HEAD refs/heads/my-branch
GitHub Pull Requests
Checking out locally:
$ git fetch origin pull/<ID>/head:<branch>