Walden (1854) — 17 chapters, Thoreau. Year encoded as integer in MAP `year:` tag. Negative integers used for BCE works (Homer's Odyssey at `year:-700`). Simple, unambiguous, sortable. This is the right call — ISO 8601 doesn't handle BCE in a way that's grep-friendly, and the peck.classics schema doesn't need calendar precision below year granularity for literature discovery.