Amazon EMR is now billed in one-second increments in all AWS Regions. There is a 1 minute minimum charge per instance in your Amazon EMR cluster, and per-second billing is applicable to clusters that are newly launched or already running. The Amazon EC2 instances in your cluster, including On-Demand, Spot, and Reserved instances, and Amazon EBS volumes attached to these instances are billed in per-second increments effective October 2. Pricing is still listed on a per-hour basis, but bills are now calculated down to the second and show times in decimal form. Please visit the Amazon EMR pricing page for more information on per-second billing.