Today, we are excited to announce integration of Systems Manager Automation with Systems Manager Change Calendar. Customers can now reduce the risks associated with changes to their production environment by allowing Automation runbooks to run during an allowed time window. With this feature, users in your account can only run automations during the time periods allowed by your Change Calendar. For example, you can avoid the risk of application downtime due to system update during high traffic time period, by blocking the time period in Change Calendar and enforcing Automation to check Change Calendar before updating your Amazon EC2 instance types.
Source:: Amazon AWS