Build an invoice reminder workflow in n8n with Google Sheets (idempotent, AU GST wording)

说明与用途

自动化、幂等的发票提醒工作流，支持时区感知日期处理、稳健的日期解析以及澳大利亚 GST 术语。

问题

Automate sending invoice reminders based on due dates while handling time zones, date formats, idempotency, and GST wording.

结果

Automated, idempotent invoice reminders with correct timezone-aware date logic, robust date parsing, and AU GST wording.

工作流

• Schedule Trigger (daily 9am, workflow timezone set)
• Google Sheets Get rows
• Code node to decide which rows need reminders
• Send Email (SMTP)
• Google Sheets Update row (match on row_number)

证据

Schedule Trigger (daily 9am, workflow timezone set) → Google Sheets "Get rows" → Code node (decide) → Send Email (SMTP) → Google Sheets "Update row" (match on row_number).

来源

daysFromDue = today − due_date, where today is the date in the workflow timezone: $today.toFormat('yyyy-MM-dd'), not new Date().toISOString()

来源

Send only if that stage's index is greater than the stored last_stage_sent index (idempotent).

来源

Send Email v2.1 appends an n8n attribution footer by default. Turn it off under Options.

来源

Google Sheets can hand you a date cell as a serial number (46312 is 17 Oct 2026), depending on the Get rows node's Options → Output Formatting → Date Formatting.

来源