-- A note can now span a period rather than one day (e.g. a holiday week).
-- entry_date remains the start of the range; end_date is NULL for a
-- single-day entry, keeping every existing row valid with no backfill.

ALTER TABLE journal_entries
  ADD COLUMN end_date DATE NULL AFTER entry_date;

INSERT IGNORE INTO schema_migrations (version) VALUES ('004_add_end_date');