-- Add the previous-day row used by rail and civil-aviation ring-ratio calculations.
-- day_index = 0 identifies the configured previous day; normal holiday days remain 1..N.
INSERT IGNORE INTO holiday_calendar
  (year, holiday_type, holiday_date, day_index, created_at, updated_at)
VALUES
  (2024, 'NATIONAL_DAY', '2024-09-30', 0, NOW(), NOW()),
  (2025, 'NATIONAL_DAY', '2025-09-30', 0, NOW(), NOW()),
  (2026, 'NATIONAL_DAY', '2026-09-30', 0, NOW(), NOW());