Datediff start date cannot be greater than the end date

[jsquaredz]

I have been using DAX DATEDIFF statement  to calculate No Days between two dates which are

Target Completion Date and Actual Completion Date

Which works all very well except now I have sometimes the Actual Completion Date is before the Target Completion Date (ie where an Action Officer performed better and completed the task before the "target" date).

However, of course, DATEDIFF doesn't like this and gives error "In DATEDIFF function, the start date cannot be greater than the end date"

Why can't this Dax function just return the negative value in this case?  Is there a way we can enhance this function to return a signed integer?

[Catcheson]

I was using the Feb 2018 version of BI Desktop and the DATEDIFF worked perfectly and did return a negative answer.  However for reasons of incompatibility with the Report Server I had to revert to the June 2017 version and I now have this problem.

I’m not sure what version you are on and when the the feature started to work but upgrading might be a solution for you.

unfortunately for me, it’s still a pain in the neck as in fact is most of Power BI!  Never again will I use software that isn’t close to being finished and operational!  

[Anonymous]

Makes totally sense what you suggest. Microsoft, Why not fix this properly or create a function what does work (to ensure existing reports do not change behaviour).

[kdaya]

HI please can someone help 

I am trying to calculate the total amount of hours between Todays date and set date that i have in my table but i keep getting the same error

DUE BY TIME = DATEDIFF(request[DueBy Time].[Date], TODAY(),HOUR)

The due by time is usually greater than the current date

Thanks,

[heidibb]

I realize this is an older topic, but I came across it when searching for a similar solution. I wanted to share that this solution also worked for me:

Days Btwn = -1 * (format(start_date, "MM-DD-YYYY") - format(end_date, "MM-DD-YYYY")) 

I needed to add the format since our dates have timestamp and I wanted the difference in days regardless of the hour. If you are ok with getting portions of days, leave off the format!

Hope this  helps someone!

[Framet · Accepted solution]

Hi,

Whilst I can't answer the "why" it can't return a negative integer for dates where the start date is after the end date I can suggest you could simply handle it with a IF statement. Test your dates if the start date is greater than the end date then change the sign of the result datediff with the dates passed to the function the other way round.

DateDiffMeasure :=
IF (
    [StartDateField] > [EndDateField],
    0 - DATEDIFF ( [EndDateField], [StartDateField], DAY ),
    DATEDIFF ( [StartDateField], [EndDateField], DAY )
)

Might work for you?

[BI_Business]

This worked well.  Thanks for posting!

[BI_Business]

This worked well.  Thanks for posting!

[hmedinaa]

It works great

Thanks,

[jsquaredz]

Thanks.  I realize there is a workaround we can wrap around the functions behaviour, but  I would like this built in Dax function so that it returns a signed integer.  Makes more sense to me that I just put in two dates and it returns the difference.

[Framet]

In that case I think your best course of action is to make a suggestion on the idea forum for the behaviour of the function be changed and see if other users in the community support it.

https://ideas.powerbi.com/forums/265200-power-bi-ideas

Many thanks

Thomas

[jsquaredz]

Looks like someone else has this same idea.  Please vote this up.  Much appreciated.

https://ideas.powerbi.com/forums/265200-power-bi-ideas/suggestions/16841479-date-diff-start-date-not...