AWS Documentation » AWS Lambda » Developer Guide » Using AWS Lambda with Other Services » Using AWS Lambda with Amazon CloudWatch Events » Schedule Expressions Using Rate or Cron

Schedule Expressions Using Rate or Cron

AWS Lambda supports standard rate and cron expressions for frequencies of up to once per minute. CloudWatch Events rate expressions have the following format.

rate(Value Unit)

Where Value is a positive integer and Unit can be minute(s), hour(s), or day(s). For a singular value the unit must be singular (for example, rate(1 day)), otherwise plural (for example, rate(5 days)).

Rate Expression Examples

Frequency	Expression
Every 5 minutes	rate(5 minutes)
Every hour	rate(1 hour)
Every seven days	rate(7 days)

Cron expressions have the following format.

cron(Minutes Hours Day-of-month Month Day-of-week Year)

Cron Expression Examples

Frequency	Expression
10:15 AM (UTC) every day	cron(15 10 * * ? *)
6:00 PM Monday through Friday	cron(0 18 ? * MON-FRI *)
8:00 AM on the first day of the month	cron(0 8 1 * ? *)
Every 10 min on weekdays	cron(0/10 * ? * MON-FRI *)
Every 5 minutes between 8:00 AM and 5:55 PM weekdays	cron(0/5 8-17 ? * MON-FRI *)
9:00 AM on the first Monday of each month	cron(0 9 ? * 2#1 *)

Note the following:

• If you are using the Lambda console, do not include the cron prefix to your expression.

• One of the day-of-month or day-of-week values must be a question mark (?).

For more information, see Schedule Expressions for Rules in the CloudWatch Events User Guide.