startofmonth & FirstDate function Issue

[skdas]

Hi All,
I was trying to get the first date from a date field or you can say a measure is having a date from which I was trying to get the first date . E.g. the measure is consisting 03-23-2017 , then I want to get 03-01-2017. For which I tried two functions we have in DAX i.e. StartOfMonth & FirstDate. But none of these functions gave me the required result. Then I tried
EOMONTH(Measure,-1)+1. And it gave me the correct answer.
I just wanted to know whether the two functions are working fine for others and I have done something wrong or, these functions are not working at all.

Thanks & Regards,
SKD

[Chiniminiz]

Hi, 

I always use the startofmonth with a calculatetable function from my date table using 

startofmonth today =
STARTOFMONTH (
CALCULATETABLE (
VALUES ( 'Date'[Date] ),
MONTH ( 'Date'[Date] ) = MONTH ( TODAY () )
)
)

It's easy to use and could also be build with DATEADD() 🙂 

Have fun!

[Eric_Zhang]

@skdas

STARTOFMONTH

EOMONTH

FIRSTDATE

You can reference the online documentation. They have different actually funtionality.

measureFirstDate = CALCULATE(SUM(Table1[value]),FIRSTDATE(Table1[date]))

measureLastDate = CALCULATE(SUM(Table1[value]),LASTDATE(Table1[date]))

startofmo = STARTOFMONTH(Table1[date])

To get the 1st day of a given date, eg in your case, you can apply EOMONTH or 

Measure  = DATE(YEAR([yourMeasure]),MONTH([yourMeasure]),1)

[Zubair_Muhammad · Accepted solution]

@skdas

Just to put it briefly

StartofMonth, EndofMonth, FirstDate  return the first date/last date in the "Date Column" which they take as argument.

Not the first date/last date of the month