I configured for my AWS account the new AWS instance scheduler https://aws.amazon.com/answers/infrastructure-management/instance-scheduler/
The problem seems that, tagging ec2-instances through a scaling group the ec2-instances are correctly stopped, but since my scaling group has Min number set to 2 AWS scaling group restarts them anyway.
I would not like to set Min number to 0, just because is useful during application redeploy.
How to make the 2 services work fine?
When you stop your EC2 instances that are controlled by Auto Scaling, then Auto Scaling will see them as "unhealthy" and it will proceed to terminate and replace them.
You have 2 options.
Option 1: Pause Auto Scaling processing while your EC2 instances are stopped. By doing this, Auto Scaling won't care that your EC2 instances are stopped and won't terminate them. Just remember to resume processing after you restart your EC2 instances.
However, AWS Instance Scheduler will not manage this for you, so you'll need to find another way to schedule your EC2 instances to stop & restart.
Option 2: Scale your Auto Scaling group to 0 and back to 2. This will result in terminating your EC2 instances (when you don't need them) and re-creating them (when you want them). This will only work if your EC2 instances are ephemeral.
Again, AWS Instance Scheduler will not manage this for you. Auto Scaling scheduled actions may be able to help you with this.