Invoice day used to be an hour of archaeology. Memory, Slack scrollback, calendar cross-referencing — reconstructing a week you lived through but can't itemize. Then you round everything down, because you're honest, and eat the difference.

With a week of automatic tracking behind you, it's ten minutes. Here's exactly how to invoice for hourly work, with the timings, so you can hold me to it.

Short answer: turn tracked time into an invoice in three steps: (1) set up categories and rules once so your work sorts itself, (2) on invoice day, export a daily summary CSV for the week — day × category × app × site; (3) paste the client's rows into your invoice template and bill. The first run takes 20 minutes; every week after, about 10.

Step 0 — The one-time setup (20 minutes, once)

Everything after this is fast because of this step. Do it once, on a quiet evening, and the sorting runs itself forever.

Create your categories. Timex ships with a starter set — Development, Productivity, Communication, Browsing, Entertainment, System — but for billing you want client-shaped ones: "Client A — Development," "Client B — Research." Categories are free; make one per billable thing (Settings ▸ Categories, then the + button).

Write your rules. This is the part that pays for the app. In Settings ▸ Categories, assign a domain to a category and it becomes a website rule; right-click a window title in Today to add a keyword rule. The ones that matter for billing look like this:

  • clientportal.com → Client B — Research
  • github.com/yourclient → Client A — Development
  • figma.com → Client A — Development
  • docs.google.com → Internal — Admin (not billable, but track it anyway)

Keep a "Manual" category for what the Mac can't see — calls, meetings, site visits. You'll use it in Step 1.

That's the whole setup. From here on, your week sorts itself while you work.

Step 1 — Log the invisible hours (2 minutes a day, or 5 on Friday)

The tracker sees your Mac. It can't see the phone call you took pacing around the kitchen, or the meeting in an actual meeting room. Two ways to handle it:

In the moment (best): after you've been away from the keyboard 5 minutes, Timex shows an away-gaps prompt — "Away 25 min · 10:05–10:30 → Add time…" Click it, pick the client category, done. Ten seconds, and the hour has a name.

On Friday (fine): open the day's timeline, spot the gaps, use the + button in the Today header ("Add time entry") — pick the category, type the window, done. Five minutes for a whole week of calls.

Either way, the record now covers your whole working day — Mac time and away time — not just the hours in front of a screen.

Step 2 — Export the week (2 minutes)

Now the part that used to be an hour.

In the Today view, pick your date range — Today, Yesterday, Last 7, Last 30, This week, This month, or a custom start–end range from the calendar. Then click the Export menu in the Today header and choose Daily summary (CSV). What lands on your disk is a table of day × category × app × site — every day of the week, every category it touched, with hours per app and per website.

This is the invoice-shaped version of your week. No timestamps to interpret, no raw log to parse — just "Tuesday, Client A — Development, 5.4 hours, of which 3.1 in VS Code and 1.9 on github.com."

(There's also a detailed CSV export if a client wants receipts — every window title, timestamped. Most don't. Some do, and it's nice to have.)

Step 3 — Paste and bill (5 minutes)

Open the CSV in Numbers or Excel. Filter by the client's category. You now have, per day: category, app, site, hours.

Paste into your invoice template, apply your rate, and bill. If you bill by project rather than hours, the same filtered rows are your evidence of scope — useful the day the client asks why the "small change" took a week.

Ten minutes, start to finish, and none of it is memory. That's the difference between a tracker that's a diary and a tracker that's a billing system: the CSV export shape. A diary you read; a billing system you paste.

The honest caveats

The first invoice takes longer than ten minutes. Expect 20–30 minutes your first time — you'll discover categories you need to create and rules you should have written. Every week after, the setup tax is already paid.

Rounding is still your call. The CSV gives you 5.4 hours; whether you bill 5.5 or 5 is between you and your engagement letter. The data's job is accuracy, not policy.

This covers your Mac-shaped work. Phone calls and meetings need Step 1's manual entries. And Timex can't split one browser tab across two clients — if you interleave two clients in one window, write the rules at the domain level and accept the approximation, or log a manual entry for the split.

The compounding part nobody prices in

The first month, this workflow saves you maybe an hour. Fine. The real money is elsewhere:

  • The scope-creep proof. "Quick fixes" on a fixed-price project show up as hours with timestamps. That data changes renegotiation conversations.
  • The underbilling you stop doing. Your first tracked week will probably surface a gap between what you remembered and what the record shows — often 5–10 hours. That gap, billed, pays for the app the first month.
  • The raise you can argue. A year of records is the strongest rate-increase evidence a solo operator can own.

A tracker without export is a mirror. A tracker with the right export shape is a billing system. Download Timex — the 100-hour trial is about two and a half work weeks, which is exactly one billing cycle. Run it through one, export the CSV, and see what your memory's been eating.

— DK