A system and method provide Time-of-Use (TOU) rate schedules that are bound by windows of time, i.e., a type of fuzzy switch time, which is bounded on both sides, rather than instantaneous switch times. The fuzzy TOU schedule defines the time of a tier switch as the end time of the first completed interval recorded after the start of some window of time. A monitoring system may be included that implements configurable usage filters that allow for the classification of usage in terms of interval data. Usage filters can be defined so that they are applied against individual interval readings, various aggregations of interval readings, and/or the statistical products of interval readings, etc. A filtering algorithm allows for the comparison of incoming and/or historical interval data against defined usage and schedule filters to determine if usage is abnormal and should be investigated further.
