Dax question on last 30 days/year

[joshcomputer1]

I am new to Power BI.....

I added a custom column in the query editor and all I want to do is add a filter for last 30 days, last 90 days, last 180 days. I figured there would be 3 columns to do this so I am working on the first one. 

if today()- [start date] <30 then 1 else 0

I have done this with the start date column being a date and with it being text and both throw an error "the name 'today' wasn't recognized. Make sure it's spelled correctly.

Any help on this is appreciated. 

[Greg_Deckler]

You're mixing DAX with your M, try DateTime.LocalNow

[joshcomputer1]

Thanks for the quick response.  I typed it in as 

=if DateTime.LocalNow() - [Start Date]<30 then 1 else 0

*Start Date is a date data type*

I am now getting this error:

Expression.Error: We cannot apply operator - to types DateTime and Date.
Details:
Operator=-
Left=4/5/2017 10:44:15 AM
Right=1/2/2017

[Vvelarde]

@joshcomputer1

Try with little modification:

=if DateTime.Date(DateTime.LocalNow()) - [Start Date]<30 then 1 else 0

[joshcomputer1]

I am getting the following error with this formula.

=if DateTime.Date(DateTime.LocalNow()) - [Start Date]<30 then 1 else 0

Expression.Error: We cannot apply operator < to types Number and Duration.
Details:
Operator=&lt;
Left=30
Right=93.00:00:00

I have changed the data type to date, date time for both columns, but still get errors. Is there an easier way to do this. I just want a 1 if less than 30 days ago from [Start Date] (which is 1/2/2017 in the column)

[Sean · Accepted solution]

@joshcomputer1

it looks like that IF statement compares Duration to Days

So try this instead...

= if Duration.Days(DateTime.Date(DateTime.LocalNow()) - [Date]) < 30 then 1 else 0

EDIT:

https://msdn.microsoft.com/en-us/library/mt253516.aspx

You have to compare the same Data Types

So the column in Red calculates the Days correctly but displays them as Duration

that's why the previous attempt was failing

all we did here is first convert the red column to days and then check - is it less than 30

Hope this helps!

[Vvelarde]

@joshcomputer1

Ok. 

Use this in the Custom Column:

if Duration.Days(DateTime.Date(DateTime.LocalNow()) - [StartDate])<30 then 1 else 0