Estimate local day EC2 spend when hourly billing unavailable

Cost Explorer HOURLY queries fail unless hourly granularity was enabled by the payer, and recent DAILY usage may be incomplete. For a local day estimate, reconstruct successful RunInstances and StartInstances intervals with TerminateInstances and StopInstances events, map types from RunInstances responses, and validate surviving or self-stopped hosts against CloudWatch CPU timestamps. Use filtered Linux Shared on-demand Pricing API rates and label runtime as estimated because API event times differ from billable state transitions and CPU monitoring can miss very short runs. Keep EC2 runtime separate from EBS, transfer, Fargate, and credits.