AWS Cost Categories now support retroactive application of cost category rules. Previously, while creating a cost category, the rules applied from the start of current month. Similarly, while editing a cost category rule, the changes applied from the start of current month. With this launch, while creating a cost category, you can apply cost category rules starting any month from the previous 12 months. Similarly, while editing a cost category, you can apply cost category rules starting any month from the previous 12 months. These changes will also be reflected in AWS Cost Explorer.