Track Japanese business-day contract deadlines with Claude, Sheets and Slack

## Deadlines written in words, counted in business days Contracts and invoices say things like "within 10 business days of receipt" or "the 20th of next month (the business day before if closed)". This workflow keeps those deadlines in a Deadlines tab. Claude only turns the wording into a small rule (type, number, month, holiday rule). Code checks the rule against the wording and counts the dates, using the Japanese national holidays from the Cabinet Office CSV plus your own company holidays. Every morning Slack lists what is overdue, due today and due soon. ### How it works 1. Read the open rows of the Deadlines tab and the holiday CSV. 2. Only new or changed wording goes to Claude. The rule is stored in the sheet, so the same wording is never sent twice. 3. Code rejects a rule whose number, day or month is not in the wording, computes the deadline and the business days left, and writes them back. 4. Rows that cannot be read become Needs review; they are never dropped. ### Setup 1. Blank Google Sheet: paste its ID in Spreadsheet ID, run Run once, select the sheet in both Google Sheets nodes. 2. Add rows: task, owner (a name or a Slack user ID), base_date (year first, like 2026-10-15), rule_text, status. 3. Credentials: Google Sheets, Anthropic, Slack (pick a channel). 4. In Config, add your company holidays and the reminder window. Publish. ### Note The deadline is a calculation from the wording you entered. Check important deadlines against the contract.