Every 20 Seconds

Use in your stack

{
  "schedule": {
    "cron": "0/20 * * * * ?",
    "timezone": "UTC"
  }
}

// 6-field: second minute hour day-of-month month day-of-week
@Scheduled(cron = "*/20 * * * * *")
public void everyTwentySeconds() {
    // ...
}

// Simpler for pure intervals — no cron parser needed:
@Scheduled(fixedRate = 20000) // milliseconds
public void everyTwentySecondsFixedRate() {
    // ...
}

Next runs

Pick a timezone to see when this expression fires next.

Variations

Common use cases

• Polling a moderately active queue or message broker.
• Refreshing a live metric or status panel during development.
• Sub-minute health checks with a 20-second detection window.
• Periodically flushing a small buffer to a downstream system.

Gotchas

• **Unix crontab cannot do this.** The 5-field format has no seconds field; its minimum is `* * * * *` (every minute). Kubernetes CronJob and GitHub Actions inherit the same limit.
• In Spring, `*/20 * * * * *` is the 6-field form (seconds first). Don't confuse it with Unix's 5-field `*/20 * * * *`, which means every 20 *minutes*.
• In Quartz, use `0/20 * * * * ?` — the `0/20` seconds field means "starting at second 0, every 20 seconds," and `?` fills the unused day-of-week field.
• For a pure interval, a `fixedRate`/`fixedDelay` loop is simpler than a cron parser. Use `@Scheduled(fixedRate = 20000)` in Spring or `tokio::time::interval` in Rust.
• Because 60 divides evenly by 20, the runs land cleanly at :00, :20, :40 — no drift within the minute.

Frequently asked questions