n8n Overtime Limits Tracker: Forms to Google Sheets & Slack

Track monthly overtime, calculate limits, and get Slack warnings automatically

This n8n workflow captures employee overtime and holiday work via an n8n Form, stores it in Google Sheets, then checks every Monday for anyone nearing monthly, rolling-average (2–6 months), or annual overtime limits—posting per-employee alerts (or an all-clear) to Slack.

What this workflow does

• Collects submissions: Receives monthly hours from an n8n Form, including employee details, the month, overtime hours, and holiday work hours.
• Validates and normalizes input: Normalizes the data, generates a per-employee-per-month key, verifies month format and hour ranges, and returns clear plain-language errors back to the form when invalid.
• Writes to Google Sheets: Saves valid entries into the MonthlyHours tab, appending or updating the same row so resubmissions for the same employee and month overwrite prior values.
• Runs weekly limit checks: Every Monday morning, reads all rows from MonthlyHours and calculates remaining capacity against:
  • the configured monthly combined cap,
  • rolling-average caps across 2–6 months (skipping averages when months are missing), and
  • the annual overtime cap.
• Notifies Slack and logs results: If someone is below the configured threshold, posts a per-employee warning to a Slack channel and appends the details to a WarningLog tab in Google Sheets. If nobody is close, posts a one-line confirmation in Slack.

Use cases

• HR/ops teams monitoring overtime compliance without manual spreadsheet review.
• Teams using n8n automation to centralize overtime reporting with Slack alerts.
• SaaS operators who need scheduled limit monitoring and audit-friendly logging in Google Sheets.

Technical details

• n8n Form for collecting monthly overtime and holiday work submissions
• Google Sheets via OAuth2 (MonthlyHours + WarningLog tabs)
• Slack via OAuth2 for warning messages and weekly all-clear
• Workflow logic implemented with nodes such as if, set, code, form, slack, and split out