Nine In The Morning, Wherever They Are — A Scheduler That Sends On Each Recipient's Own Clock

What you'll do

A scheduled send engine you own end to end: a validated recipient roster that cannot hold a fake time zone, a versioned campaign contract that states its daylight-saving policy as data rather than as a comment, a pure occurrence calculator property-tested against every zone in the IANA database on your machine, a SQLite ledger where exactly-once is enforced by a unique index rather than by careful coding, a lease-based claimer that two overlapping runs cannot both win, a transport layer that classifies every SMTP failure into retry, suppress, or stop-the-run, a suppression gate that outranks every campaign and is re-checked at the last moment before sending, a persisted rate budget that defers rather than drops, an explain-one-recipient command that reconstructs any decision months later, and two drills you have actually run: a daylight-saving gap that makes the intended hour not exist, and a runner killed mid-send that still produces exactly one message.