Cannot get quarterly difference matrix to work

[CJDK]

I am trying to build a matrix that compares the differences from one quarter to another - actual differences or percentage differences.

I have tried copying several examples without success. The examples use numeric values (e.g. Sales in USD), but the values I am using are not numeric, but strings (e.g. "Sales visit" or "Contract signed"). Therefore I cannot use SUM and have been trying with COUNT instead:

SupportTypeCount = COUNT(MyTable[Support type])

In the matrix the rows are the "Support types" and the columns are Quarters:

Quarter = FORMAT([Date], "\QQ yyyy")

So far, so good. But I cannot find the correct measure for the values - I have tried numerous combinations, also using a Date Calendar, but all have failed:

QuarterlySupportChange = DIVIDE(MyTable[SupportTypeCount], CALCULATE([SupportTypeCount], DATEADD('Date'[Date], -1,QUARTER)),0)-1
Supports LQ = CALCULATE([SupportTypeCount],DATEADD(MyTable[Date],-1,QUARTER))
Supports LQ = CALCULATE(COUNT(MyTable[Support type]),DATEADD('Date'[Date]-1,QUARTER))
Supports LQ = CALCULATE(COUNT(MyTable[Support type]),PREVIOUSQUARTER(MyTable[Date]))
Supports LQ = CALCULATE(COUNT(MyTable[Support type]),DATEADD(MyTable[Date],-1,QUARTER))

Any help pointing out my error will be very gratefully received!

CJ

[CJDK]

Many thanks Amit - again! 🙏

Your video was very instructuve and I have been able to use that input and your corrections to springboard to my final measure:

QuarterlySupportChange = DIVIDE(COUNT(MyTable[Support type]), CALCULATE COUNT(MyTable[Support type]), DATEADD('Date'[Date], -1,QUARTER)),0)-1

Please note a missing comma in your measures:

'Date'[Date],

MANY thanks!

CJ

[amitchandak · Accepted solution]

@CJDK , with help from date table marked as date table , these should work

Supports LQ = CALCULATE(COUNT(MyTable[Support type]),DATEADD('Date'[Date]-1,QUARTER))
Supports LQ = CALCULATE(COUNT(MyTable[Support type]),datesqtd(DATEADD('Date'[Date]-1,QUARTER)))

Make sure the date table is marked as a date table, there is no timestamp in the fact/table table

refer

Why Time Intelligence Fails - Power bi 5 Savior Steps for TI: https://youtu.be/OBf0rjpp5Hw