Amazon CloudWatch Alarms adds wall clock evaluation windows

Amazon CloudWatch Alarms now supports wall clock evaluation windows, allowing users to align alarm evaluations to fixed calendar boundaries like the top of the hour or start of the week. This feature helps prevent false alarms for scheduled or business-aligned workloads by evaluating events within specific daily or weekly periods, rather than using a continuous sliding window. It is particularly useful for scenarios like daily backups, ensuring alarms trigger correctly even if event timings vary slightly. Customers can also specify time zones, with automatic handling of daylight saving transitions.