til/git/review-commits-from-before-a-certain-date.md

Review Commits From Before A Certain Date

I was recently looking at data in a 3rd-party tool and saw that there was a very distinct shift in what was being recorded a couple years prior on a specific date. I wanted to see what changes had been made to the codebase a day or two before the shift.

Rather than scrolling all the way back in git log, I can tell git log to show me all commits from before a certain date.

Let's say that date of interest is May 1st, 2021. I can use the --until flag with git log. However, I should note that --until is an exclusive range, so I'll need to specify May 2 2021 if I want to start seeing commits on May 1.

$ git log --until='May 2 2021'

Because git log shows commits in reverse chronological order, I'll start seeing commits from May 1st and then as I scroll, I'll see older and older commits.

From here I can scan commits messages and look for one that I want to dig into. I'd then use git show <sha> to explore a specific one further.

This is synonymous with --before.

See man git-log for more details.