3 month average with year change

[sjpusat16]

Hi, I am working on a measure to calculate the average of the previous 3 months' sales. I figured this out for months that are all in the same year, then I realized that in January the measure wouldn't work. Currently I calculate 3 measures for Month-1, Month-2, and Month-3, and then add them up and divide by 3 to get the average. Here is what Month-2 looks like (the other 2 measures are the exact same just different offsets of the month):

Month-2 = CALCULATE(SUM(Query3[Amt]), RollingCalendar[Month] = MONTH(TODAY())-2, RollingCalendar[Year] = YEAR(MAX(RollingCalendar[Date])))

Obviously when the 3 month interval crosses over a new year, this will create an issue. Can someone point me in the right direction on how to cover this exception?

[rubayatyasmin · Accepted solution]

Hi, @sjpusat16 

use EDATE dax func. 

for example, 

RollingCalendar[Month] = MONTH(EDATE(TODAY(), -2)),

RollingCalendar[Year] = YEAR(EDATE(TODAY(), -2))

refer to this doc: https://learn.microsoft.com/en-us/dax/edate-function-dax