Auto Shutdown and Start Amazon EC2 Instance

Can I automatically start and terminate my Amazon instance using Amazon API? Can you please describe how this can be done? I ideally need to start the instance and stop the instance at specified time intervals every day.

Does stopping and starting EC2 instance change IP?

Actually, When you stop/start your instance, the IP address will change. If you reboot the instance, it will keep the same IP addresses. Unfortunately, it is not possible for us to reassign the address to your instance as that address would have been released back into the pool used by other EC2 instances.

Just in case somebody stumbles on this ye old question, nowadays you can achieve the same thing by adding a schedule to an auto scaling group: increase the amount of instances in an auto scaling group to 1 at certain times and decrease it back to 0 afterwards.

And since this answer is getting a lot of views, I thought to link to a very helpful guide about this: Running EC2 Instances on a Recurring Schedule with Auto Scaling