Blending "Time of Day" Analysis with Calendar/Date Analysis

Usually, when we talk about "time" in Power Pivot, we're talking about the Calendar/Date flavor: How much have things changed from yesterday to today. What are our Month to Date numbers, and how do those compare against the same period last year? Let's call this "macro-trending." But time of day is also often interesting: what are the trends WITHIN a day? Let's call this "micro-trending."