Because DAX has no base data type for duration, adding durations has always been a little problematic, especially when attempting to display the end result in the HH:mm:ss format. This recipe allows you to aggregate durations and display them in an actual duration format (HH:mm:ss) within a column chart!
I will be forever grateful to Konstantinos Ioannou for first teaching me about DAX's VAR statement when I created an early version of this calculation. In addition, I would be remiss if I did not mention Chelsie Eiden, an intern that worked for Microsoft and added the crucial feature that allows custom display formatting for fields while preserving their underlying data type.