AWS SAM ScheduledEvent error: "Parameter ScheduleExpression is not valid"

Question

I'm trying to setup an EventBridge Scheduled Event for my Lambda Function using the SAM CLI.

My desired cron expression is:

cron(0 0 * * ? *)

My template.yml file:

Events:
  ScheduledEvent:
    Type: Schedule
    Properties:
      # Every day at 0:00
      Schedule: cron(0 0 * * ? *)

I've tried setting the cron expression on the AWS console and it's considered valid.

I've tried these other expressions in my template.yml file:

cron(0 0 * * ? *)
cron(0 0 * * * *)
cron(0 0 ? * * *)
cron(0 1 * * ? *)
cron(1 1 * * ? *)
0 0 * * ? *
"cron(0 0 * * ? *)"

but they always return the same error when I try to deploy the stack.

What's the error in my cron expression?

Answer 1

I deployed a sample Node.js function from this repository https://github.com/awsdocs/aws-lambda-developer-guide/tree/main/sample-apps/blank-nodejs after adding the event config to its template. This is the event config I added:

Events:
  ScheduledEvent:
    Type: Schedule
    Properties:
      # Every day at 0:00
      Schedule: cron(0 0 * * ? *)

It worked and after that I tried to deploy my original function (with no changes to its template). Now my function was deployed successfully.