Tracking when a branch was created is difficult in Git as it does not directly store the timestamps of your branch creation. However, you can derive the branch creation date using the commit history, reflogs, and other Git commands.
In this blog, we are going to explore different methods to determine the branch creation date.
Table of Contents
Understanding Git’s Branch Creation Process
Before we move ahead into the blogs about the various methods to check when the branch was created, it is very important to understand Git’s Branch creation process. Let us briefly understand the process here.
When you create a new branch, Git will not record any direct explicit timestamp for the creation event. Instead, it tracks the first commit that is made on the branch, the checkout event in case the branch was created from another branch, and the divergence point from the main branch. Therefore finding the earliest commit made on a branch is the best way to derive its creation time.
Various Methods to Determine when a Git Branch was Created
Method 1: Using Git Reflog
The first method to determine when a branch was created is by using Git Reflog. It tracks all the changes to the branch heads, which includes when a new branch is checked out. This indicates when a branch was created, therefore it is best for recent branch creations but it may not work if the reflog was cleaned.
Command:
git reflog show <branch-name>
Output:
abc1234 HEAD@{3}: branch: Created from master
Method 2: Finding the first Commit on a Branch
Suppose the reflog data is unavailable, you can check the first commit made after the branch was created.
Command:
git log --reverse --format="%H %cd" <branch-name>
This will list down all the commits in chronological order. The first entry is the branch’s first commit. This works even if the reflog is cleared but will not be helpful if no commits are made after the branch creation.
Method 3: Checking Merge Base with Git Merge-Base
Suppose the branch was created from a different branch, finding the merge base (common ancestor) will help you.
Command:
git merge-base --fork-point main <branch-name>
Or you can use:
git log --oneline --graph --decorate --all
This will help in the estimation of when the branch was created on the basis of the last shared commit. It is useful to track the branches which were created long ago but it is not always 100% correct.
Method 4: Using Git Log to Find the Oldest Commit
Now suppose all the previous methods mentioned above do not help, you can check the oldest commit on the branch. It is mostly reliable for branches with unique histories but is not useful for recently created branches that do not have commits.
Command:
git rev-list --reverse <branch-name> | head -1
Then, check the commit timestamp:
git show --format="%cd" <commit-hash>
Conclusion
Finding the branch creation time is not easy, but the methods mentioned above will help you to estimate when it was first introduced. Various methods such as by using reflog for finding the recent branches or using git merge-base for merged branches will eventually help you determine when the branch is created.