Cron expressions reference - Amazon EventBridge
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Cron expressions reference

Cron expressions have six required fields, which are separated by white space.

Syntax

cron(fields)
Field Values Wildcards

Minutes

0-59

, - * /

Hours

0-23

, - * /

Day-of-month

1-31

, - * ? / L W

Month

1-12 or JAN-DEC

, - * /

Day-of-week

1-7 or SUN-SAT

, - * ? L #

Year

1970-2199

, - * /
Wildcards

  • The , (comma) wildcard includes additional values. In the Month field, JAN,FEB,MAR includes January, February, and March.

  • The - (dash) wildcard specifies ranges. In the Day field, 1-15 includes days 1 through 15 of the specified month.

  • The * (asterisk) wildcard includes all values in the field. In the Hours field, * includes every hour. You can't use * in both the Day-of-month and Day-of-week fields. If you use it in one, you must use ? in the other.

  • The / (slash) wildcard specifies increments. In the Minutes field, you could enter 1/10 to specify every tenth minute, starting from the first minute of the hour (for example, the 11th, 21st, and 31st minute, and so on).

  • The ? (question mark) wildcard specifies any. In the Day-of-month field you could enter 7 and if any day of the week was acceptable, you could enter ? in the Day-of-week field.

  • The L wildcard in the Day-of-month or Day-of-week fields specifies the last day of the month or week.

  • The W wildcard in the Day-of-month field specifies a weekday. In the Day-of-month field, 3W specifies the weekday closest to the third day of the month.

  • The # wildcard in the Day-of-week field specifies a certain instance of the specified day of the week within a month. For example, 3#2 would be the second Tuesday of the month: the 3 refers to Tuesday because it is the third day of each week, and the 2 refers to the second day of that type within the month.

    Note

    If you use a '#' character, you can define only one expression in the day-of-week field. For example, "3#1,6#3" is not valid because it is interpreted as two expressions.

Limitations

  • You can't specify the Day-of-month and Day-of-week fields in the same cron expression. If you specify a value or a * (asterisk) in one of the fields, you must use a ? (question mark) in the other.

  • Cron expressions that lead to rates faster than 1 minute are not supported.

Examples

You can use the following sample cron strings when creating a rule with schedule.

Minutes Hours Day of month Month Day of week Year Meaning

0

10

*

*

?

*

Run at 10:00 am (UTC+0) every day

15

12

*

*

?

*

Run at 12:15 pm (UTC+0) every day

0

18

?

*

MON-FRI

*

Run at 6:00 pm (UTC+0) every Monday through Friday

0

8

1

*

?

*

Run at 8:00 am (UTC+0) every 1st day of the month

0/15

*

*

*

?

*

Run every 15 minutes

0/10

*

?

*

MON-FRI

*

Run every 10 minutes Monday through Friday

0/5

8-17

?

*

MON-FRI

*

Run every 5 minutes Monday through Friday between 8:00 am and 5:55 pm (UTC+0)

0/30

20-2

?

*

MON-FRI

*

Run every 30 minutes Monday through Friday between 10:00 pm on the starting day to 2:00 am on the following day (UTC)

Run from 12:00 am to 2:00 am on Monday morning (UTC).

The following example creates a rule that runs every day at 12:00pm UTC+0.

aws events put-rule --schedule-expression "cron(0 12 * * ? *)" --name MyRule1

The following example creates a rule that runs every day, at 2:05pm and 2:35pm UTC+0.

aws events put-rule --schedule-expression "cron(5,35 14 * * ? *)" --name MyRule2

The following example creates a rule that runs at 10:15am UTC+0 on the last Friday of each month during the years 2019 to 2022.

aws events put-rule --schedule-expression "cron(15 10 ? * 6L 2019-2022)" --name MyRule3