I’m trying to create something that seems pretty easy (in theory), but am having a hard time figuring out how to do it.
I am currently showing some sales data on a line chart. The sales peak in 2Q and 3Q and fairly flat in 1Q and 4Q. In order to smooth out the lines, my boss has asked to see the data on rolling trailing 12 month basis; so that the data point for January 2021 would be the sum of (Feb 2020 - Jan 21), February 2021 would be the sum of (Mar 2020 - Feb 2021), etc. I’m thinking it would be a custom period, but I’m having trouble setting it up. Any guidance is appreciated.