Cloud infrastructure provider Amazon Web Services today announced the launch of Scheduled Reserved Instances, a new flavor of its Reserved Instances, or virtual slices of physical servers in Amazon data centers that are reserved ahead of time, unlike the more popular On-Demand Instances.

Customers can now sign up to run Scheduled Reserved Instances at specified dates and times. The new instances could be useful for companies that need to do computational work at certain times known in advance. And of course, they cost 5-10 percent less than regular On-Demand Instances.

“They allow you to reserve capacity on a recurring basis with a daily, weekly, or monthly schedule over the course of a one-year term,” AWS chief evangelist Jeff Barr wrote in a blog post on the news. “After you complete your purchase, the instances are available to launch during the time windows that you specified.”

This is just another option available to AWS’¬†million-strong customer base. Recently, Amazon has fleshed out its options beyond traditional On-Demand Instances, which initially launched in 2006. Last year Amazon acquired ClusterK, a startup that built systems for running fault-tolerant applications on top of Amazon’s Spot Instances.

In September, the Google Cloud Platform, one of the most prominent AWS competitors, launched Preemptible VMs, a kind of answer to AWS Spot Instances that cost less than on-demand instances and can be shut down at any time. Google Cloud Platform, Microsoft Azure, and IBM SoftLayer have not yet launched an option for scheduling reserved VMs.

The new Scheduled Reserved Instances are available from three Amazon regions — U.S. East (Northern Virginia), U.S. West (Oregon), and Europe (Ireland) — and only through AWS’ C3, C4, M4, and R3 instances, Barr wrote.

He added that support for AWS’ Auto Scaling, CloudFormation, and Lambda services are coming later.