Cron Expression Cheat Sheet

Everything you need to write, read, and debug cron expressions — in one page. Every operator, all the shorthands, 30+ common patterns, and the key differences between platforms (Unix, Quartz, AWS EventBridge, Kubernetes, GitHub Actions).

1. Anatomy of a Cron Expression

A standard Unix cron expression has five space-separated fields:

Field	Range	Special values
Minute	0–59
Hour	0–23
Day of month	1–31	L (last), W (nearest weekday) — Quartz only
Month	1–12	JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC
Day of week	0–7 (0 and 7 = Sunday)	SUN, MON, TUE, WED, THU, FRI, SAT; L, # — Quartz only

2. Operators Reference

Operator	Name	Example	Meaning
*	Wildcard / Any	* * * * *	Match every value in this field
,	List	0 9,17 * * *	At 9am and 5pm — comma-separated values
-	Range	0 9-17 * * *	Every hour from 9am to 5pm inclusive
/	Step	*/5 * * * *	Every 5 minutes — step through the range
L	Last	0 0 L * *	Last day of the month (Quartz / Spring only)
W	Nearest weekday	0 0 15W * *	Nearest weekday to the 15th (Quartz only)
#	Nth weekday	0 10 * * 1#2	Second Monday of the month (Quartz only)
?	No specific value	0 0 ? * 1	Used in day-of-month or day-of-week when the other is set (Quartz / AWS)

Step operator examples

Expression	Meaning
*/5 (minute)	Every 5 minutes: 0, 5, 10, 15 … 55
0-30/5 (minute)	Every 5 minutes, only in the first half-hour: 0, 5, 10, 15, 20, 25, 30
*/2 (hour)	Every 2 hours: 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22
1/2 (hour)	Every 2 hours starting at 1am: 1, 3, 5, 7 … 23

3. Special Shorthands

Most Unix cron implementations support these shorthands as alternatives to a 5-field expression. Note: AWS EventBridge, GitHub Actions, and Kubernetes do not support these — use the explicit 5-field form.

Shorthand	Equivalent	Runs…
@yearly / @annually	0 0 1 1 *	Once per year at midnight on January 1st
@monthly	0 0 1 * *	Once per month at midnight on the 1st
@weekly	0 0 * * 0	Once per week at midnight on Sunday
@daily / @midnight	0 0 * * *	Once per day at midnight
@hourly	0 * * * *	Once per hour at the top of the hour
@reboot	—	Once at system startup (crontab only)

4. Common Cron Patterns

Sub-hourly

Expression	Meaning	Notes
* * * * *	Every minute	1,440 runs/day
*/2 * * * *	Every 2 minutes
*/5 * * * *	Every 5 minutes	Most common polling interval
*/10 * * * *	Every 10 minutes
*/15 * * * *	Every 15 minutes	Quarter-hourly
*/30 * * * *	Every 30 minutes	Same as 0,30 * * * *

Hourly & multi-hour

Expression	Meaning	Notes
0 * * * *	Every hour (top of hour)	Also: @hourly
30 * * * *	Every hour at :30
0 */2 * * *	Every 2 hours	At 00:00, 02:00, 04:00…
0 */4 * * *	Every 4 hours	At 00:00, 04:00, 08:00, 12:00, 16:00, 20:00
0 */6 * * *	Every 6 hours	Midnight, 6am, noon, 6pm
0 */12 * * *	Every 12 hours	Midnight and noon
0 9,17 * * *	9am and 5pm daily	Comma list

Daily

Expression	Meaning	Notes
0 0 * * *	Every day at midnight	Also: @daily
0 6 * * *	Every day at 6am
0 9 * * *	Every day at 9am	Most common "morning" job
0 12 * * *	Every day at noon
0 18 * * *	Every day at 6pm
0 23 * * *	Every day at 11pm	Good for nightly backups

Weekly

Expression	Meaning	Notes
0 0 * * 0	Every Sunday at midnight	Also: @weekly
0 0 * * 1	Every Monday at midnight
0 9 * * 1	Every Monday at 9am	Weekly digest
0 9 * * 1-5	Weekdays at 9am	Mon–Fri only
0 9 * * 6,0	Weekends at 9am	Sat and Sun
0 9 * * 1,3,5	Mon, Wed, Fri at 9am

Monthly & yearly

Expression	Meaning	Notes
0 0 1 * *	1st of every month at midnight	Also: @monthly
0 9 1 * *	1st of every month at 9am	Monthly report
0 0 15 * *	15th of every month at midnight	Mid-month billing
0 0 1 1 *	January 1st at midnight	Also: @yearly
0 0 1 */3 *	First day of every quarter	Jan 1, Apr 1, Jul 1, Oct 1
0 0 1 6,12 *	June 1st and December 1st	Twice-yearly

5. Platform Differences

Platform	Fields	Key differences
Unix / Linux crontab	5 (min hour dom month dow)	Supports @shorthands and @reboot. Timezone set via CRON_TZ env var or system timezone.
Quartz / Spring	6 (sec min hour dom month dow) or 7 (+ year)	Extra seconds field. Supports L, W, # operators. ? used in dom/dow to avoid conflict.
GitHub Actions	5 (standard Unix)	Always UTC. Minimum interval is every 5 minutes. Actual trigger may be delayed by up to 15 minutes under load.
AWS EventBridge	6 (min hour dom month dow year)	Adds year field. Uses ? instead of * in dom/dow when the other is specified. Always UTC.
Kubernetes CronJob	5 (standard Unix)	Timezone support added in Kubernetes 1.27 via spec.timeZone. Older versions default to controller timezone (usually UTC).
node-cron	5 or 6 (with optional seconds)	Optional 6th field for seconds. Uses system timezone by default; pass {timezone: 'America/New_York'} option.
APScheduler (Python)	Named parameters	Uses keyword args (hour, minute, day_of_week) rather than a string expression. Accepts */5 notation as string values per field.

AWS EventBridge conversion examples

Unix cron	EventBridge equivalent
0 9 * * *	cron(0 9 * * ? *)
0 9 * * 1-5	cron(0 9 ? * MON-FRI *)
*/5 * * * *	cron(*/5 * * * ? *)
0 0 1 * *	cron(0 0 1 * ? *)

6. Common Gotchas

Day-of-month and day-of-week interact unexpectedly

In most Unix cron implementations, if you specify both a day-of-month and a day-of-week, cron uses an OR — not an AND. 0 0 1 * 1 fires on the 1st of the month and every Monday, not only on Mondays that fall on the 1st.

Timezone is the server timezone, not yours

Cloud servers (AWS, GCP, Azure, Heroku, Render) are almost always UTC. 0 9 * * * on a UTC server fires at 9am UTC — which is 4am US Eastern, 5am US Central. Set CRON_TZ=America/New_York in Linux crontab, or spec.timeZone in Kubernetes.

GitHub Actions schedule delays

GitHub Actions cron jobs can be delayed by up to 15 minutes (sometimes more) during peak load. They also require a minimum interval of 5 minutes — * * * * * is silently treated as */5 * * * *.

Overlapping jobs

If a job takes longer than its interval, the next run starts before the previous one finishes. Use flock -n /tmp/lockfile.lock (Linux) or check for a PID file at the start of your script to skip concurrent runs.

0 and 7 both mean Sunday

Most cron implementations accept both 0 and 7 for Sunday in the weekday field. Some tools (especially Quartz) use 1=Sunday, 7=Saturday — always verify when switching scheduler libraries.

See also: Cron job not running? 10 reasons why  ·  Cron vs systemd timers  ·  GitHub Actions cron schedule guide  ·  Expression reference library