AWS instance scheduleredit
The StackZone instance scheduler is a great money-saving feature that can automatically turn on and off tagged EC2 instances and RDS instances, based on a schedule you define. This means for example, you could automate your development EC2 instances to start at 8:30 in the morning, and turn them all off at 17:30 in the evening, on Mondays to Fridays.
You can build additional schedules to meet your needs. All you need to do once this is active is tag your resources and StackZone will take care of the rest.