Send automatic reminders for overdue invoices tracked in Airtable

flowchart TD trig(["runs every morning"]):::trigtime s0["check invoices for overdue"]:::task s1[["calculate days overdue"]]:::mi s2["send reminder email"]:::svc s3[("update invoice record")]:::store trig --> s0 s0 -->|"one per each overdue invoice"| s1 s2 --> s3 gx{"× how many days overdue"}:::gate s1 --> gx p00["send friendly reminder"]:::task gx -->|"slightly overdue"| p00 p10["send urgent reminder"]:::task gx -->|"very overdue"| p10 p20["send final reminder"]:::task gx -->|"long overdue"| p20 jn{"○ update record"}:::gate p00 --> jn p10 --> jn p20 --> jn jn --> s2 out[/"reminder email sent per overdue invoice"/]:::out pay{{"fewer late payments without awkward chasing"}}:::pay s3 --> out out --> pay classDef task fill:#e7f6fe,stroke:#34b8f0,color:#2c2a29 classDef svc fill:#f6f8fa,stroke:#7c8795,color:#2c2a29 classDef mi fill:#e7f6fe,stroke:#0079a8,color:#2c2a29,stroke-width:2px classDef human fill:#fff,stroke:#0079a8,color:#0079a8 classDef store fill:#f6f8fa,stroke:#0079a8,color:#2c2a29 classDef trig fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigtime fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigdata fill:#8ad4f5,stroke:#0079a8,color:#06314c,font-weight:bold classDef gate fill:#fff,stroke:#e8a23d,color:#6b4708,font-weight:bold classDef out fill:#1f9d6b,stroke:#167a53,color:#fff,font-weight:bold classDef pay fill:#06314c,stroke:#021f33,color:#fff