Forum Discussion
Helper IIIDate function not working as intended?
Well, DATEADD should work just fine, I have never seen a bug with that functions, and it should be the way to go.
If, on the other hand, you want to do it manually, then you can follow a simple technique. Create a Y12M column in the Date table that contains (Year * 12 + Month). With that column in place, you can freely move back and forth with months by adding to that value the offset.
So, MAX ( Date[Y12M] - 3 ) results in three months ago, no matter which year you are into.
But, if I were you, I would try to understand what's wrong with DATEADD, as this is the best way of expressing date offsets.
Have fun with DAX!
Alberto Ferrari
http://www.sqlbi.com
Community Champion
Community ChampionMicrosoft's information on the DATE function, clearly explains what happens if you supply a day number > last day of the month (and lots of other information as well)
VooseHi Marcelbeug,
I think you may have misread the formula, I'm not adding days... I'm adding months and the place you've linked would be useful if I were adding more months or days than there are in a given month of day however I am not I am adding 3 Months in a particular scenario.
Thanks
Voose
- MarcelBeug
If you add 3 months to DATE(2018,3,31) then you end up in DATE(2018,6,31), which returns July 1, 2018, because June has only 30 days. I don't think I misread anything.
- Voose
- AlbertoFerrari
Most Valuable Professional
Well, DATEADD should work just fine, I have never seen a bug with that functions, and it should be the way to go.
If, on the other hand, you want to do it manually, then you can follow a simple technique. Create a Y12M column in the Date table that contains (Year * 12 + Month). With that column in place, you can freely move back and forth with months by adding to that value the offset.
So, MAX ( Date[Y12M] - 3 ) results in three months ago, no matter which year you are into.
But, if I were you, I would try to understand what's wrong with DATEADD, as this is the best way of expressing date offsets.
Have fun with DAX!
Alberto Ferrari
http://www.sqlbi.com- Voose
AlbertoFerrari - I feel like I've just had a celebrity reply to my post! :smileyembarrassed:
Even more embarrsing, I left my original test of the DateAdd function in my model and I've just gone back to look at it and all of the dates seem to be filled in.... the only difference I can see is in the data type being Date and not Date time, that being said switching it back doesn't seem to effect it.
On an aside, please come to england for more talks :)
Thanks
Voose