How do I create a new Git branch from an old commit? [duplicate]

Possible Duplicate / a more recent/less clear question
Branch from a previous commit using Git

I have a Git branch called jzbranch and have an old commit id: a9c146a09505837ec03b.

How do I create a new branch, justin, from the information listed above?

git checkout -b NEW_BRANCH_NAME COMMIT_ID

This will create a new branch called 'NEW_BRANCH_NAME' and check it out.

("check out" means "to switch to the branch")

git branch NEW_BRANCH_NAME COMMIT_ID

This just creates the new branch without checking it out.

in the comments many people seem to prefer doing this in two steps. here's how to do so in two steps:

git checkout COMMIT_ID
# you are now in the "detached head" state
git checkout -b NEW_BRANCH_NAME