What is the order of cron fields?

Minute, hour, day of month, month, day of week. Quartz and Spring put seconds in front; AWS adds a year at the end.

What does the question mark mean in cron?

“No specific value”. Quartz and AWS require it in one of the two day fields; standard crontab doesn’t accept it.

How do I write “every 90 minutes”?

Cron can’t express intervals that don’t divide the hour or day evenly in one line. Use two entries, such as 0 0-21/3 * * * and 30 1-22/3 * * *.

Are month and weekday names case-sensitive?

No. JAN, Jan and jan are equivalent in every dialect covered here.

Cron Syntax Cheatsheet: Fields, Symbols & Examples

Fields and allowed values

Field	Values	Notes
Second	0–59	Quartz, Spring and 6-field crons only
Minute	0–59	First field in crontab and AWS
Hour	0–23	24-hour clock
Day of month	1–31	L, W and LW in Quartz, Spring, AWS
Month	1–12 or JAN–DEC	Names are case-insensitive
Day of week	0–7 or SUN–SAT	Quartz and AWS: 1–7, 1 = Sunday
Year	1970–2199	Optional in Quartz, required in AWS

Special characters

Symbol	Meaning	Example
*	Any value	* * * * * — every minute
,	List of values	0 9,17 * * * — 09:00 and 17:00
-	Range	0 9 * * 1-5 — weekdays at 09:00
/	Step	/15 * * * — every 15 minutes
?	No specific value (day fields)	0 0 12 ? * MON — Quartz
L	Last day / last weekday	0 0 0 L * ? — last day of month
W	Nearest weekday	0 0 9 15W * ? — weekday nearest the 15th
#	Nth weekday of the month	0 0 9 ? * 2#1 — first Monday

Macros

Macros	Standard crontab
@yearly / @annually	0 0 1 1 *
@monthly	0 0 1 * *
@weekly	0 0 * * 0
@daily / @midnight	0 0 * * *
@hourly	0 * * * *

Reading order

Read an expression from the smallest unit to the largest: 30 2 * * 1 is minute 30 of hour 2 on any day of the month, in any month, when the weekday is Monday — 02:30 every Monday. In Quartz and Spring, prepend the seconds field; in AWS, append the year.

Common pitfalls

*/7 in the minute field does not mean “every seven minutes forever”: it restarts at each hour, so it fires at 0, 7, … 56 and then at 0 again. Restricting both day fields in crontab means either can match. And 0 in the day-of-week field is invalid in Quartz and AWS, where the week starts at 1.

Frequently asked questions

What is the order of cron fields?: Minute, hour, day of month, month, day of week. Quartz and Spring put seconds in front; AWS adds a year at the end.
What does the question mark mean in cron?: “No specific value”. Quartz and AWS require it in one of the two day fields; standard crontab doesn’t accept it.
How do I write “every 90 minutes”?: Cron can’t express intervals that don’t divide the hour or day evenly in one line. Use two entries, such as 0 0-21/3 * * * and 30 1-22/3 * * *.
Are month and weekday names case-sensitive?: No. JAN, Jan and jan are equivalent in every dialect covered here.