Amazon’s AWS cloud computing platform is introducing a new pricing tier today that will make its service more affordable for customers who only need to run their cloud-based applications during certain hours of the day or only on certain days of the month.

With this new pricing tier, called Scheduled Reserved Instances, AWS users can reserve instances for pre-defined blocks of time on their own daily, weekly and monthly schedules. You simply tell Amazon when and for how long you will need a machine and it’ll be ready to go at those times.

To do this, you have to lock yourself in to a one-year term, but in return, you get a discount that brings rates down by about 5 to 10 percent compared to Amazon’s standard on-demand rates.

The size of the discount depends on when you are using your scheduled machines. During peak hours, you get a 5 percent discount, and during off-peak hours (which are basically the weekends), you get a 10 percent discount.

The new pricing model is currently only available for machines in Amazon’s US East (North Virginia), US West (Oregon) and EU (Ireland) regions.

Overall, this seems like a smart move. A lot of cloud workloads aren’t constant, after all. Maybe you only need to run a certain calculation every weekday afternoon, for example. Or you only run your billing calculations on the first day of every month.

If you use AWS, Azure or Google’s Cloud Platform, you’d spin up a machine on those days and then shut it down again once you’re done. Until now, you’d just pay the standard on-demand price while you were running those machines.