I would like to know how to do calculations with Grouped dates. For example, my data is divided in rounds between specific dates during the year (each year the same dates). When I want to compare one year vs the previous one I can't seem to use Fixed LODs

see the attached red tab i recreated the LOD - your calculation just needed the sales measure included in it (think maybe you typed it all the way in and tableau did not auto pick up the measure

Jim