Cron Expression Cheat Sheet

The Five Fields

┌───────────── minute (0–59)
│ ┌───────────── hour (0–23)
│ │ ┌───────────── day of month (1–31)
│ │ │ ┌───────────── month (1–12 or JAN–DEC)
│ │ │ │ ┌───────────── day of week (0–6, Sun=0, or SUN–SAT)
│ │ │ │ │
* * * * *

Special Characters

Char	Name	Meaning	Example
*	Wildcard	Any value	* * * * * — every minute
,	List	Multiple values	1,15 * * * * — at minute 1 and 15
-	Range	Inclusive range	0 9-17 * * * — hours 9 through 17
/	Step	Every Nth value	*/5 * * * * — every 5 minutes
?	No value	Skip this field	0 0 ? * MON — (Quartz/AWS only)
L	Last	Last day	0 0 L * * — last day of month (Quartz)
W	Weekday	Nearest weekday	0 0 15W * * — nearest weekday to 15th (Quartz)
#	Nth weekday	Nth occurrence	0 0 ? * 5#3 — 3rd Friday (Quartz)

Field Ranges

Field	Allowed Values	Allowed Special Characters
Minute	0–59	, - * /
Hour	0–23	, - * /
Day of month	1–31	, - * / ? L W
Month	1–12 or JAN–DEC	, - * /
Day of week	0–6 or SUN–SAT (0=Sunday)	, - * / ? L #

Common Schedules

Expression	Description
* * * * *	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 6 * * *	Daily at 6:00 AM
0 9 * * 1-5	Weekdays at 9:00 AM
0 9,18 * * *	Daily at 9 AM and 6 PM
0 0 * * 0	Every Sunday at midnight
0 0 * * 1	Every Monday at midnight
0 0 1 * *	First of every month at midnight
0 0 1,15 * *	1st and 15th at midnight
0 0 1 1 *	January 1st at midnight (yearly)
30 2 * * 0	Every Sunday at 2:30 AM

Crontab Shortcuts

These shortcuts work in Linux/macOS crontab:

Shortcut	Equivalent	Description
@reboot	—	Run once at startup
@yearly	0 0 1 1 *	Once a year (Jan 1)
@annually	0 0 1 1 *	Same as @yearly
@monthly	0 0 1 * *	Once a month (1st)
@weekly	0 0 * * 0	Once a week (Sunday)
@daily	0 0 * * *	Once a day (midnight)
@midnight	0 0 * * *	Same as @daily
@hourly	0 * * * *	Once an hour (:00)

Day of Week Numbering

Day	Standard cron	Quartz / Spring
Sunday	0 (or 7)	1
Monday	1	2
Tuesday	2	3
Wednesday	3	4
Thursday	4	5
Friday	5	6
Saturday	6	7

Platform Differences

Platform	Fields	Seconds?	Timezone	Notes
Linux crontab	5	No	System TZ	Supports @shortcuts
Kubernetes CronJob	5	No	UTC (default)	timeZone field since v1.27
GitHub Actions	5	No	UTC only	Min 5-min interval; best-effort timing
GitLab CI	5	No	Configurable	Set in pipeline schedule UI
AWS EventBridge	6	No (year field)	UTC or specified	Uses ?; format: cron(0 9 ? * MON *)
Spring @Scheduled	6	Yes (first field)	App TZ	0 0 9 * * MON-FRI (note: seconds first)
Quartz	6–7	Yes (first field)	App TZ	Supports L, W, #, ?

Common Mistakes

Mistake	Why It’s Wrong	Fix
* * * * * when you meant hourly	Fires every minute (1440×/day)	0 * * * *
0 0 * * 1-7	Day 7 is also Sunday (duplicate)	0 0 * * 0-6 or 1-7 depending on system
Both DOM and DOW set	Standard cron uses OR logic	Set one to *; use ? in Quartz
*/7 expecting “every 7 min” evenly	Fires at 0,7,14,21,28,35,42,49,56 (9× not 8×)	This is correct but uneven across hours
Forgetting Spring starts with seconds	0 * * * * = every minute in Spring	Prepend 0: 0 0 * * * *
Using @hourly in Kubernetes	Not supported; use 0 * * * *	K8s only accepts 5-field expressions

Quick Examples by Use Case

Backups:

• Full backup nightly at 3 AM: 0 3 * * *
• Incremental every 6 hours: 0 */6 * * *
• Weekly full on Sunday 2 AM: 0 2 * * 0

Monitoring:

• Health check every 5 min: */5 * * * *
• Disk space alert every hour: 0 * * * *
• SSL cert check weekly: 0 9 * * 1

Reports:

• Daily digest at 8 AM: 0 8 * * *
• Weekly report Monday 9 AM: 0 9 * * 1
• Monthly billing on the 1st: 0 8 1 * *

Maintenance:

• Log cleanup daily at 4 AM: 0 4 * * *
• Cache flush every 15 min: */15 * * * *
• DB vacuum on Sunday 3 AM: 0 3 * * 0

Tools and Resources

• Cron Expression Parser & Generator — validate and visualize any expression
• Unix Timestamp Converter — debug timestamps in cron job logs
• Cron Expression Syntax Explained — full guide with real-world examples
• Unix Timestamp Guide — understand timestamps in job output
• man 5 crontab — the official Linux reference
• crontab.guru — another interactive cron editor