Cron Job Examples — Common Cron Expressions Reference

Q: What does */ mean in a cron expression?

The */n syntax is a "step" value — it means "every n units". */5 in the minute field means "every 5 minutes" (0, 5, 10, 15, ..., 55). */2 in the hour field means "every 2 hours" (0, 2, 4, 6, ..., 22). You can combine with ranges: 8-18/2 means "every 2 hours from 8 to 18" (8, 10, 12, 14, 16, 18). Steps are widely supported but not in all cron implementations — check your platform's documentation.

Reference guide for common cron expressions with human-readable descriptions. Build and validate cron schedules for Linux cron, GitHub Actions, Kubernetes, and AWS EventBridge.

Understanding Cron Expression Syntax

A cron expression has 5 fields: minute hour day-of-month month day-of-week. Each field accepts a number, range (1-5), step (*/15), list (1,3,5), or wildcard (*). Use the cron generator to build expressions visually and get a human-readable description before deploying.

Every minute: * * * * *
Every hour: 0 * * * * (at minute 0)
Daily at midnight: 0 0 * * *
Weekdays at 9 AM: 0 9 * * 1-5
First of every month: 0 0 1 * *

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This page: Cron expression reference — common patterns with descriptions
Cron Expression Generator: Build and validate cron expressions visually
Kubernetes CronJob: K8s spec.schedule field expressions
GitHub Actions Schedule: on:schedule cron triggers

Common Cron Expression Reference

* * * * * — Every minute
*/5 * * * * — Every 5 minutes
*/15 * * * * — Every 15 minutes
*/30 * * * * — Every 30 minutes
0 * * * * — Every hour (at :00)
0 */2 * * * — Every 2 hours
0 */6 * * * — Every 6 hours
0 0 * * * — Daily at midnight
0 2 * * * — Daily at 2:00 AM (common for nightly backups)
0 9 * * 1-5 — Weekdays at 9:00 AM
0 9 * * 1 — Every Monday at 9:00 AM
0 0 * * 0 — Every Sunday at midnight
0 0 1 * * — First day of every month
0 0 L * * — Last day of every month (some systems)
0 0 1 1,4,7,10 * — Quarterly (Jan, Apr, Jul, Oct 1st)
0 0 1 1 * — Annually on January 1st

Cron Field Reference

Field 1 — Minute: 0–59 | * any | */5 every 5 min
Field 2 — Hour: 0–23 | * any | 9-17 business hours
Field 3 — Day of month: 1–31 | * any | 1,15 1st and 15th
Field 4 — Month: 1–12 or JAN–DEC | * any
Field 5 — Day of week: 0–7 (0 and 7 both = Sunday) or SUN–SAT | 1-5 Mon–Fri

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Frequently Asked Questions

What does */ mean in a cron expression?

The */n syntax is a "step" value — it means "every n units". */5 in the minute field means "every 5 minutes" (0, 5, 10, 15, ..., 55). */2 in the hour field means "every 2 hours" (0, 2, 4, 6, ..., 22). You can combine with ranges: 8-18/2 means "every 2 hours from 8 to 18" (8, 10, 12, 14, 16, 18). Steps are widely supported but not in all cron implementations — check your platform's documentation.

How do I run a cron job on the last day of the month?

Standard cron has no built-in "last day of month" field. The workaround: schedule for day 28 and check in your script if it's the last day before executing. For systems that support it (newer cron implementations, Quartz Scheduler, some cloud schedulers), the L character in the day-of-month field means "last day" — 0 0 L * *. For standard cron (Linux, most systems), test with: 0 0 28-31 * * [ "$(date +\%d -d tomorrow)" = "01" ] && your_command

How do I run a cron job every weekday at a specific time?

Use values 1–5 in the day-of-week field (1=Monday, 5=Friday): 0 9 * * 1-5 runs every weekday at 9:00 AM. Note: in cron, 0 and 7 both represent Sunday — 0-5 would include Sunday. Always use 1-5 for Monday-to-Friday. To run on a specific weekday only, use a single value: 0 9 * * 1 runs only on Mondays. Combine with month ranges for quarterly weekday runs: 0 9 * 1,4,7,10 1 runs on Monday in January, April, July, and October.