TimeSplitter
One command turns a week of AI-assisted work into an honest timesheet.
The question I kept dodging
When you build with AI all day, one simple question gets strangely hard to answer: how long did that actually take? The work is real, but it is scattered. Some of it is commits. Some of it is an hour spent steering Claude through a refactor that lands as a single line of git history. Some of it is a Codex session, a pull request, a ticket moving across a board.
I needed an honest number for invoices and timesheets, and a stopwatch was never going to give me one. You do not start and stop a timer every time you switch between thinking, prompting and reviewing. So the hours just quietly went missing.
The evidence was already there
None of that work is actually invisible. Every commit, every coding session, every PR and every ticket already carries a timestamp. The trail exists. Nobody reads it back.
So the idea was simple: reconstruct the day from the evidence, not from memory. Treat every timestamped event as a point, group the points that cluster into real sessions, and you get an activity-based estimate of when you were working and for how long. Not a stopwatch. A reconstruction of a day you have already lived.
How it works
Run one command: /timesplitter. It reads your git history across every clone and worktree of the project, your Claude Code and Codex sessions, your merged and open GitHub PRs, and your Linear activity. Anything it cannot find, it skips cleanly. Then it buckets all of it into work blocks and turns that into three things.
A markdown worklog you can read, day by day and week by week, with what you actually worked on. An interactive HTML dashboard, styled with shadcn: hours per day, commits, sessions, a sortable table, light and dark. And a CSV, so the numbers drop straight into whatever you invoice from.
The first run reconstructs the whole project in minutes. After that it catches up to now in seconds, so the timesheet stays current without ever being rebuilt from scratch.
Built with: Claude Code skills / git / GitHub CLI / Linear / shadcn UI
Free and open
TimeSplitter is free and open source. It runs entirely on your machine, against tools you already use, and keeps a human-readable worklog as the source of truth. The repo is live on GitHub. If you bill for AI-assisted work, or you just want an honest picture of where the hours went, it is worth the one command.
Part of the Rolling Waves work archive.