In an inbound ACD call overlapping two consecutive time intervals, I_ACDTIME records the call in the first interval for a duration spanning the start of the call until the end of the first interval and continues to record the call in the second interval for a duration spanning the start of the second interval until the end of the call. In a similar situation, ACDTIME records the entire duration of the call in the second interval because that is the interval in which the call ends. In other words, I_ACDTIME tracks the ACD time by interval whereas ACDTIME tracks the ACD time by the call.