DAX

[Anonymous]

The formula below works for calculating the cumulative total by year, displaying null values when past current date. Is there a way I can make the formula stop calculating the cumulative total at the previous month rather than the current month. 

I would expect changing the line below to -1 to work but this only removes January from my pivot table: 

var __prevMonthEndDate = EOMONTH(__currentMaxDate, -1)

Cumulative E&A Wells (Previous Month):=var __currentMaxDate = MAX('Calendar'[Date])
var __currentMinDate = MIN('Calendar'[Date])
var __today = TODAY()
var __prevMonthEndDate = EOMONTH(__currentMaxDate, 0)
var __cumulativevalue =
CALCULATE(
COUNTROWS('FM Full Export'),
DATESYTD('Calendar'[Date]),
'Calendar'[Date] <= __prevMonthEndDate,
ALLSELECTED('Calendar'[Date])
)
var __shouldDisplay =
--check if the current period is fully contained in the future
NOT(__currentMinDate >= __today)
return
IF(__shouldDisplay, __cumulativevalue)

Many thanks

[Stachu]

what is selected in the slicer on the calendar table? or how is it desplayed in the visual?
from what I see the measure should return the same results  even if you skip the 

'Calendar'[Date] <= __prevMonthEndDate,

because it will always be more constrained by the

DATESYTD('Calendar'[Date]),

so I am quite puzzled how it gives you the 'previous month' - previous in reference to what exactly?