Automated Overdue Invoice Reminder System

This workflow automates invoice payment reminders by triggering on new or updated rows in a Google Sheets spreadsheet containing invoice data, such as due dates in column D. It fetches the current date, calculates the number of overdue days using a date helper, and employs a router to direct the flow based on overdue thresholds: polite reminders after 7 days, firmer notices at 14 days, and urgent demands at 21 days. Emails are customized with increasing urgency to prompt payment without manual i