Create a YAML file for a cronjob that runs monthly using the image linux/java.

 A job definition must have  url and a schedule. You can also optionally specify a description, timezone, target, and retry_parameters:

url

Required. The URL in your app to which you want the Cron service to send job requests.

schedule

Required. Defines the schedule of when you want the job to run, see the syntax below.

description

Optional. Describes your cron job, which is visible from within the Cloud Console.

timezone

Optional Time Zone

Refer to link: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

If you want to use it for your job schedule. If you don't specify a time zone, the schedule uses, which is also known as GMT.

cron:
- description: "daily summary job"
  url: /tasks/summary
  schedule: every 24 hours
- description: "monday morning mailout"
  url: /mail/weekly
  schedule: every monday 09:00
  timezone: Australia/NSW
- description: "new daily summary job"
  url: /tasks/summary
  schedule: every 24 hours
  target: beta