I have a line chart that is pulling in data that has a "week ending" field for each record.

I set the "data type" in the date field to different aggregation levels (Week, Month, Quarter, Year) and the chart still shows a point for each week (doesn't group by higher levels). The labels across the bottom of the chart change (see picture) but not the chart itself. Week ending chart correctly shows a point for each week Drilling all the way up to Year it changes the labels below, but not the chart.

I'm stumped. What am I doing wrong?