I Taught AI to Update My Leave Tracker. Here Is Every Prompt I Typed.

By RIM · September 2026

Every approved leave email used to cost me the same ten minutes. Open the Excel tracker. Find the employee. Add the dates to the log sheet. Update the summary sheet. Update the balance sheet the employees see. Double-check the arithmetic, because a wrong leave balance is the kind of mistake people remember.

Multiply that by every employee, every leave request, every month. It is not hard work — it is repeated work, and repeated work is exactly what AI is good at taking off your plate.

So I built what Claude calls a skill: a saved set of instructions that it follows the same way every time. Now, when an approved leave email arrives, I attach the email and the tracker, type one line, and every sheet gets updated for me. No coding was involved at any point. I described my process in plain English, the way I would explain it to a new colleague, and that was enough.

Here is exactly how I did it, prompt by prompt, so you can do the same with your own tracker.

What you need

Two things: access to Claude's Cowork mode (in the Claude desktop app — it is the version built for working with your files), and your leave tracker Excel file. That is it. You do not need to know what a macro is, and there is no formula to write.

Step 1 — Describe your process like you are talking to a colleague

The first message is not technical. You simply say what happens in your workflow. Mine was almost word for word this:

Claude asked a few clarifying questions back — what types of leave the tracker handles (annual leave, sick leave, days in lieu), and what the approval emails look like. Answer in plain language. This conversation is the building process.

Step 2 — Share the actual Excel file

This is the step that decides whether the skill works. Upload the real .xlsx file, not a screenshot. Claude needs to read the sheet names, the columns, and the existing data to understand how your tracker is organised.

Claude read the file, worked out how the three sheets connect, and then packaged everything it had learned into a skill file with a save button. One click, and the skill was installed.

Step 3 — Use it every day with one line

From then on, the daily routine looks like this: attach the approved leave email (if it is an Outlook forward, save it as a PDF first), attach the tracker, and type:

Claude reads the email, identifies the employee, the dates and the leave type, updates all three sheets, and hands back the updated file. The ten-minute job became a one-line job. Always attach both files — the email and the tracker. It needs both to do its work.

Step 4 — Refine it in plain English (this is the real magic)

The first version will not be perfect, and that is fine — because fixing it does not require touching anything technical either. You just describe what looks wrong.

My real example: the skill was recording a used day in lieu as one working day of leave, which quietly deducted it from the annual leave balance. Wrong — a day in lieu is already covered by the extra day the employee earned. So I typed this:

Claude corrected the current file, updated the skill's rules so the mistake cannot happen again, and gave me the new version to save. That is the whole maintenance process: notice, describe, save. You can refine as many times as you need.

Step 5 — Share it with your team

The finished skill is a small file. Send it to a colleague, they click save in their own Cowork, and it works identically for them. The rules you refined — like my day-in-lieu fix — travel with it. Your process knowledge, packaged.

The whole thing on one screen

The honest part

Check the output. Especially the first few runs, open the updated file and look at what changed — that is how I caught the day-in-lieu issue in the first place. The AI does the typing and the arithmetic; the accountability stays with you, exactly as it should. After the early corrections, mine has been boringly reliable — and boring is precisely what you want from a leave tracker.

The bigger point is not about leave. It is that the repeated, rule-based parts of back-office work — the ones that eat your week ten minutes at a time — can now be described once and delegated. If you can explain a process to a colleague, you can turn it into a skill.