To specify how AWS CloudFormation handles updates for the MinSize, MaxSize, and DesiredCapacity properties when the AWS::AutoScaling::AutoScalingGroup resource has an associated scheduled action, use the AutoScalingScheduledAction policy. With scheduled actions, the group size properties of an Auto Scaling group can change at any time. When you update a stack with an Auto Scaling group and scheduled action, AWS CloudFormation always sets the group size property values of your Auto Scaling group to the values that are defined in the AWS::AutoScaling::AutoScalingGroup resource of your template, even if a scheduled action is in effect. If you do not want AWS CloudFormation to change any of the group size property values when you have a scheduled action in effect, use the AutoScalingScheduledAction update policy to prevent AWS CloudFormation from changing the MinSize, MaxSize, or DesiredCapacity properties unless you have modified these values in your template.