Cron expression for first day of month

Use 0 0 1 * * to run at midnight on day 1 of every month.

Common monthly variants
  • 0 0 1 * * → first day at 00:00
  • 30 2 1 * * → first day at 02:30
  • 0 8 1 */3 * → first day every 3rd month at 08:00

If you process finance/reporting, use idempotent jobs so retries don’t duplicate outputs. Also pin timezone explicitly to avoid “ran on previous date” surprises.