Skip to main content
cancel
Showing results for 
Search instead for 
Did you mean: 

Vote for your favorite vizzies from the Power BI Dataviz World Championship submissions. Vote now!

Reply
erezbenmoshe
Advocate I
Advocate I

DATEDIFF

DATEDIFF doesn't show the expected difference.  I am trying to calculate "Months from first purchase".  

Both columns are the same date format.  The difference I get is not correct.

 

This is a calcualted column:

Months from first purchase = DATEDIFF(FactSalesCache[FirstDate], FactSalesCache[Date], MONTH)
 
 

Capture.JPG

 

Thanks,

Erez

1 ACCEPTED SOLUTION
jdbuchanan71
Super User
Super User

It looks like you pulled that column into a visual and the field is set to SUM.  My guess is the second line represents 3 records in your data set (4 months diff * 3 = 12) and the third line is covering 2 records.  Try changing the field to show the AVERAGE.

View solution in original post

4 REPLIES 4
nilimarodrigues
Helper III
Helper III

Could it be your date format? I tried with MM/DD/YYYY format and DATEDIFF works perfectly fine.

Another alternate formula could be:

DIFFERENCE = month('SAMPLE'[FIRSTSALE])-month('SAMPLE'[FIRSTPURCHASE])
Nathaniel_C
Community Champion
Community Champion

ddiff.PNG

 

Hi @erezbenmoshe ,

Works here.





Did I answer your question? Mark my post as a solution!

Proud to be a Super User!




jdbuchanan71
Super User
Super User

It looks like you pulled that column into a visual and the field is set to SUM.  My guess is the second line represents 3 records in your data set (4 months diff * 3 = 12) and the third line is covering 2 records.  Try changing the field to show the AVERAGE.

You are right!! I am embarrassed that I did not figure it out myself 🙂

Helpful resources

Announcements
Power BI DataViz World Championships

Power BI Dataviz World Championships

Vote for your favorite vizzies from the Power BI World Championship submissions!

Sticker Challenge 2026 Carousel

Join our Community Sticker Challenge 2026

If you love stickers, then you will definitely want to check out our Community Sticker Challenge!

January Power BI Update Carousel

Power BI Monthly Update - January 2026

Check out the January 2026 Power BI update to learn about new features.

FabCon Atlanta 2026 carousel

FabCon Atlanta 2026

Join us at FabCon Atlanta, March 16-20, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.