topic Re: How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)? in DAX Commands and Tips

How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)?

JustinDoh1 — Tue, 28 Oct 2025 21:10:25 GMT

I have following measure:

ForecastMonths = DATEDIFF(

FIRSTDATE ('Table'[Survey Date]),

LASTDATE ('Calendar'[Month Year]),

MONTH

)

I am trying to adjust the result (which comes in number of month) to one more/less month.

I would like the result to be either 91 or 89.

How do I go about doing it?

Thanks for help.

Re: How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)?

djurecic — Tue, 28 Oct 2025 20:52:18 GMT

Hi JustinDoh1 ,

You can use EDATE on the LASTDATE to achieve this:

https://learn.microsoft.com/en-us/dax/edate-function-dax

Re: How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)?

parry2k — Tue, 28 Oct 2025 20:52:33 GMT

JustinDoh1 not sure what you are trying to achieve, when you add or subtract:

ForecastMonths = DATEDIFF( FIRSTDATE ('Table'[Survey Date]), LASTDATE ('Calendar'[Month Year]), MONTH ) + 1 // or -1

Re: How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)?

JustinDoh1 — Tue, 28 Oct 2025 21:13:13 GMT

parry2k Thank you and sorry.

I guess I need to use -1.

Can I ask you one more question?

How can I wrap so that this condition only applies if value is 0 or greater than 0 so that there is no -1?

I guess I am trying to use IF statement for the result.. Thanks.

Re: How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)?

parry2k — Tue, 28 Oct 2025 22:02:17 GMT

JustinDoh1 sure here it is, change the condition as per your needs

ForecastMonths = VAR __Months = DATEDIFF( FIRSTDATE ('Table'[Survey Date]), LASTDATE ('Calendar'[Month Year]), MONTH ) RETURN IF ( __Months >= 0, __Months - 1, __Months )

Re: How to subtract one more month to DATEDIFF result (only if total is 0 or greater than 0)?

Kedar_Pande — Wed, 29 Oct 2025 10:27:24 GMT

JustinDoh1

ForecastMonths =
VAR Diff = DATEDIFF(
FIRSTDATE('Table'[Survey Date]),
LASTDATE('Calendar'[Month Year]),
MONTH
)
RETURN
IF(Diff >= 0, Diff - 1, Diff)

If this answer helped, please click Kudos or mark as Solution.
-Kedar
LinkedIn: https://www.linkedin.com/in/kedar-pande