Who controls the past, controls the future: who controls the present, controls the past. The mutability of the past is the central tenet of Ingsoc. Past events, it is argued, have no existence, but survive only in written records and in human memories. The past is whatever the records and the memories agree upon. And since the Party git is in full control of all records and in equally full control of the minds of its members, it follows that the past is whatever the Party git chooses to make it.

– Linus Torvalds, probably

git-backdate

git-backdate helps you to change the date of one or multiple commits to a new date or a range of dates.

Features

• Understands business hours, and that you might want to have your commits placed inside or outside of them.
• You can also except specific days or date ranges (e.g. vacation, illness …)
• Commits are randomly distributed within the given time window, while retaining their order. No 12:34:56 for you anymore!
• Given a single commit, git-backdate will automatically assume that you want to rebase the entire range from there to your current HEAD.
• Sets author date and committer date so you don't have to look up how to set both of them every time you fudge a commit timestamp.
• Python, but with near-zero dependencies (see below; only sed and date), so you can just download and run it without Python package management making you sad.

Usage

Backdate all your unpushed commits to the last three days, and only during business hours:

git backdate origin/main "3 days ago..today" --business-hours

Backdate only some commits to have happened outside of business hours:

git backdate 11abe2..3d13f 2023-07-10 --no-business-hours

Backdate only the current commit to a human readable time:

git backdate HEAD "5 hours ago"

Use ALL the features, e.g. excluding weekends and specific days and backdating only a range of commits:

git backdate 11abe2..3d13f 2023-07-01..2023-07-30 --business-hours --except-days 2023-01-05,2023-07-20..2023-07-24

Installation

Drop the git-backdate file somewhere in your PATH or wherever you like:

curl https://raw.githubusercontent.com/rixx/git-backdate/main/git-backdate > git-backdate
chmod +x git-backdate

The magic of git will now let you use git backdate as a command.

Requirements

git-backdate tries to only require git and Python. However, it also relies on

• sed if you want to backdate more than the most recent commit ^{for perfectly fine reasons, don't worry about it}
• date if you want to pass date descriptions like "last Friday" or "2 weeks ago". If you use git-backdate on MacOS and want to use this feature, you will need to run the command with GIT_BACKDATE_DATE_CMD="gdate" git backdate …, as native date on MacOS does not support the --date flag.

… why.

I started various versions of this in uni, when I did my assignments last minute and wanted to appear as if I had my life together. I still sometimes use it like that (especially to make the 3am commits look less deranged), but there have been new and surprising use cases. Most of these have been contributed by friends and do not reflect on me, nor do they represent legal or career advice:

• Did work things outside work hours, but don't want to nudge your workplace culture into everybody working at all times.
• Worked an entire weekend for a client, but don't want them to get used to it and start calling you on every weekend.
• Made some fixes during a boring meeting, but pretended to pay attention throughout.
• Want to confuse your coworkers by making it look like you were committing code while doing a company-wide presentation.
• <your reason here, please share with the class>

Caveats

Commit dates are part of a commit's metadata. Changing a commit's date changes its hash. You very likely only want to run git backdate on commits that you have not pushed yet, because otherwise you would have to --force push your new history. I know, I know, you're using --force-with-lease, so you won't destroy data, but your collaborators or integrations will still be somewhat miffed.

Also, obviously, use with care and compassion.