Cron Expression Patterns

This guide covers common cron expression patterns, tips for choosing the right schedule, and pitfalls to avoid.

Common patterns

High-frequency monitoring

Expression	Schedule	Use case
* * * * *	Every minute	Critical health checks, uptime monitoring
*/2 * * * *	Every 2 minutes	Near-real-time status polling
*/5 * * * *	Every 5 minutes	Standard health checks
*/15 * * * *	Every 15 minutes	Periodic data freshness checks
*/30 * * * *	Every 30 minutes	Semi-frequent syncs

Standard schedules

Expression	Schedule	Use case
0 * * * *	Every hour (at :00)	Hourly aggregation, cache refresh
0 */2 * * *	Every 2 hours	Periodic batch processing
0 */6 * * *	Every 6 hours	Quarterly reports, data syncs
0 */12 * * *	Every 12 hours	Twice-daily maintenance

Daily schedules

Expression	Schedule	Use case
0 0 * * *	Daily at midnight	Nightly cleanup, log rotation
0 2 * * *	Daily at 2 AM	Off-peak data processing
0 9 * * *	Daily at 9 AM	Morning reports, notifications
30 8 * * 1-5	Weekdays at 8:30 AM	Business-hours only tasks

Weekly and monthly

Expression	Schedule	Use case
0 0 * * 1	Every Monday at midnight	Weekly reports
0 9 * * 5	Every Friday at 9 AM	End-of-week summaries
0 0 1 * *	First of the month at midnight	Monthly billing, reports
0 0 15 * *	15th of the month at midnight	Mid-month checks

Staggering schedules

If you have multiple crons that run at the same interval, stagger their start times to avoid thundering-herd effects on your endpoints:

# Instead of all at :00
0 * * * *   # Cron A — every hour at :00
5 * * * *   # Cron B — every hour at :05
10 * * * *  # Cron C — every hour at :10

For daily crons, spread them across the early morning hours instead of all at midnight:

0 0 * * *   # Job A — midnight
0 1 * * *   # Job B — 1 AM
0 2 * * *   # Job C — 2 AM

Timezone considerations

Cron expressions are evaluated in UTC. If your business logic depends on local time zones, convert your desired local time to UTC:

Local time (US Eastern, UTC-5)	UTC equivalent	Cron expression
9 AM ET	2 PM UTC	0 14 * * *
Midnight ET	5 AM UTC	0 5 * * *
5 PM ET	10 PM UTC	0 22 * * *

Tip

Keep a note in your cron name about the intended local time, e.g., “Daily Report (9 AM ET)” — this makes it easier to audit your schedules.

Pitfalls to avoid

Running too frequently

Every-minute crons (* * * * *) consume your monthly request quota quickly. A cron firing every minute uses 43,200 requests per month. Use 5-minute intervals (*/5 * * * *) unless you genuinely need per-minute resolution.

Long-running endpoints with short intervals

If your endpoint takes 90 seconds to respond but the cron fires every minute, you will have overlapping executions. Each execution is independent — Recuro does not wait for the previous one to finish. Set your interval longer than your expected response time, or set a shorter timeout_seconds and fix the slow endpoint.

Forgetting about DST

Because cron expressions use UTC, daylight saving time shifts will affect the local-time equivalent of your schedule. A cron at 0 14 * * * (UTC) is 9 AM Eastern Standard Time but 10 AM Eastern Daylight Time. If exact local time matters, adjust your cron expression seasonally or schedule at a time that is acceptable in both offsets.

Next steps

• Cron Schedules — Full concept reference
• Creating a Cron Schedule — Step-by-step guide
• Retry Strategy Design — For queue-based jobs