Calculate % change in [ID] where the user can input the starting month to compare to.

[E_K_]

Want to calculate the % change in distinct count of [ID] per month, where the user can pick the starting month. the date column is [Start Time] which contains date time values, both columns are in the table 'Incidents'.

What I currently have (that only produces blanks, even if I filter on month.

Does the measure work and I need some selector visual to input the start month to compare to, or does the dax code need fixing too?

% Change =

VAR SelectedMonth = SELECTEDVALUE('Incidents'[Start Time])

VAR StartMonth = CALCULATE(

    FIRSTNONBLANK('Incidents'[Start Time], MAX('Incidents'[ID])),

    FILTER('Incidents', MONTH('Incidents'[Start Time]) < SelectedMonth)

)

VAR StartValue = CALCULATE(

    DISTINCTCOUNT('Incidents'[ID]),

    MONTH('Incidents'[Start Time]) = MONTH(StartMonth)

)

VAR EndValue = CALCULATE(

    DISTINCTCOUNT('Incidents'[ID]),

    MONTH('Incidents'[Start Time]) = SelectedMonth

)

RETURN DIVIDE(EndValue - StartValue, StartValue) * 100

[amitchandak]

@E_K_ , You should use date table and time intelligence

examples

MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD('Date'[Date]))
last MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD(dateadd('Date'[Date],-1,MONTH)))
last month Sales = CALCULATE(SUM(Sales[Sales Amount]),previousmonth('Date'[Date]))
MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD('Date'[Date]))
last MTD Sales = CALCULATE(SUM(Sales[Sales Amount]),DATESMTD(dateadd('Date'[Date],-1,MONTH)))
last month Sales = CALCULATE(SUM(Sales[Sales Amount]),previousmonth('Date'[Date]))

Time Intelligence, Part of learn Power BI https://youtu.be/cN8AO3_vmlY?t=27510
Time Intelligence, DATESMTD, DATESQTD, DATESYTD, Week On Week, Week Till Date, Custom Period on Period,
Custom Period till date: https://youtu.be/aU2aKbnHuWs&t=145s

[E_K_]

@amitchandak  this clearly does not fit my use case. You are suggesting TD measures which are not what I am after