Cron Every 6 Hours
The */6 in the hour field means "every 6th hour." This runs at 12:00 AM, 6:00 AM, 12:00 PM, and 6:00 PM — four times per day.
Cron Expression
0 */6 * * *Field Breakdown
| Field | Value | Meaning |
|---|---|---|
| Minute | 0 | At minute 0 |
| Hour | */6 | Every 6th hour (0, 6, 12, 18) |
| Day of Month | * | Every day (1-31) |
| Month | * | Every month (1-12) |
| Day of Week | * | Every day of the week (0-6) |
Variations
0 */6 * * *Every 6 hours (12AM, 6AM, 12PM, 6PM)0 0,6,12,18 * * *Equivalent explicit form0 3/6 * * *Every 6 hours starting at 3 AM (3, 9, 15, 21)Common Use Cases
- SSL certificate expiry checks
- Large database backup rotations
- Quarterly report aggregation within the day
- DNS propagation monitoring
- External API data sync (rate-limit friendly)
Tips & Best Practices
Four times per day is ideal for jobs that need same-day freshness without hourly overhead.
Offset with 3/6 to run at 3 AM, 9 AM, 3 PM, 9 PM — avoids peak load at midnight and noon.