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I just want to get a quick glance at the history of a project by having git log show only the commit date, nothing else. How can we best do that?

Update:

It turns out I was actually asking for the author date, which is what is shown by git log. To see the committer date too, which can be different, run git log --pretty=fuller.

See also here: Why is git AuthorDate different from CommitDate?

To help make this point that there are different dates: to set an author date when running git commit, use:

git commit ---date "<date>"

To set also the committer date, you'd have to do:

GIT_COMMITTER_DATE="<date>" git commit --date "<date>"

See here: How can one change the timestamp of an old commit in Git?

Gabriel Staples
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2 Answers2

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If you want to see only the committer date (the date the commit was written with it's current ID):

git log --format=%cd

If you want to see only the author date (the date the commit was originally written, but may differ from the committer date if the commit was amended, rebased, cherry-picked, etc, which caused it to get a new commit ID):

git log --format=%ad

More info on the difference between committer and author dates: Why git AuthorDate is different from CommitDate?.

Dates can be displayed in different ways. Here's a list of built-in options.

Also, if you don't want to use a pager, just add --no-pager after the git command, like this:

git --no-pager log --format=%ad
Gabriel Staples
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TTT
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  • So when someone first types in `git commit` for a brand-new set of changes, and a timestamp is added to the commit message, is that considered the "commiter" date or the "author" date, or both? – Gabriel Staples Mar 07 '22 at 18:21
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    @GabrielStaples in that case, both dates would be the same. You can view the current log to see them both and get an idea of when they differ, using: `git log --pretty=fuller`. Equally importantly as those dates differing, is that the people doing them can differ too! – TTT Mar 07 '22 at 18:25
  • Docs for different formatting can be found here: https://git-scm.com/docs/git-log#Documentation/git-log.txt-emHem – Fusion Sep 14 '22 at 18:18
  • @Fusion that link looks a lot like the one in the answer, despite being a different url. ;) – TTT Sep 14 '22 at 18:22
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1. The easy way:

(This answer was the first answer; this part was added after @TTT wrote the comment below which taught me this easier way).

# ad = author date
git log --format=%ad

# cd = committer date
git log --format=%cd

%cd stands for "Committer Date", apparently. Contrast that with %ad, which stands for "Author Date". (I'm not sure what the differences are nor how or why these dates would differ).

Thank you, @TTT. Now that I see how that works, I found the appropriate format string sections in the documentation:

Do man git log, then search for the regular expression format:<format-string> by pressing / and typing that in and pressing Enter. Searching for %cd also jumps down to that section.

2. The hard way (my initial attempt):

Tested on Linux Ubuntu:

One way to get the author date (--format=%ad, above, as I now know after-the-fact) is to filter the output of git log through grep. Here is the answer for git log HEAD. Replace HEAD with any branch name or commit hash you want.

See just the dates for all commits:

git log HEAD | grep 'Date:' | grep -o '   .*$' | grep -o '[^\r\n\t\f\v ].*$'

Sample output:

Sun Apr 26 19:17:49 2020 -0700
Sun Apr 26 16:51:21 2020 -0700
Sun Apr 26 15:35:16 2020 -0700
Sat Apr 25 23:21:37 2020 -0700
Sat Apr 25 23:12:07 2020 -0700
Sat Apr 25 23:06:44 2020 -0700
Tue Apr 14 23:02:34 2020 -0700
Sun Apr 5 23:26:20 2020 -0700
Sun Apr 5 23:20:34 2020 -0700
Sun Apr 5 18:08:44 2020 -0700
Sun Apr 5 17:56:08 2020 -0700
Sun Apr 5 10:06:04 2020 -0700
Sat Apr 4 20:58:33 2020 -0700
Sat Mar 21 14:38:53 2020 -0700
Thu Mar 19 20:37:27 2020 -0700
Thu Mar 19 18:16:55 2020 -0700
Thu Mar 19 18:01:53 2020 -0700

Or, to just see the most-recent date only, add -1:

git log -1 HEAD | grep 'Date:' | grep -o '   .*$' | grep -o '[^\r\n\t\f\v ].*$'

Output:

Sun Apr 26 19:17:49 2020 -0700

...or to see just the oldest date, use $(git rev-list --max-parents=0 HEAD) instead of HEAD (again, replace HEAD in that command with the appropriate branch or commit you'd like to view):

git log -1 $(git rev-list --max-parents=0 HEAD) | grep 'Date:' \
    | grep -o '   .*$' | grep -o '[^\r\n\t\f\v ].*$'

Output:

Thu Mar 19 18:01:53 2020 -0700

Explanation

  1. $(git rev-list --max-parents=0 HEAD) gets the commit hash of the first commit.
    1. See my answer here: How to show first commit by 'git log'?
  2. grep 'Date:' finds only lines with the text Date: in them.
  3. grep -o ' .*$' strips off the Date: part by matching only the 3 spaces and the text following that.
    1. For the -o part, see: Can grep show only words that match search pattern?
  4. grep -o '[^\r\n\t\f\v ].*$' strips off the preceding spaces by matching only non-whitespace chars.
    1. See my answer here: Unix & Linux: Any non-whitespace regular expression
  5. -1 in git log means: "just 1 commit"
  6. HEAD is the currently-checked-out commit hash
Gabriel Staples
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    I'm confused. Don't you just want `git log --format=%cd` ? – TTT Mar 07 '22 at 18:06
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    Also, your question says "commit" date which I assumed you meant "committer" date. Looks like this answer wanted "author" date. – TTT Mar 07 '22 at 18:13
  • @TTT, to your first question: yes, thank you. To your 2nd question: I don't understand the difference: what is the difference between committer date and author date? When might they differ? Why? Feel free to add that to your answer. – Gabriel Staples Mar 07 '22 at 18:17
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    I updated my answer to explain the differences. – TTT Mar 07 '22 at 18:21