DAX TOTALYTD() - Duplicate Date Error

Evening,

In tabular data models (power bi, tables & relationships) it's best to create a related date table to your fact table.

Your fact table typically contains all of your data, for example transaction log.

Your Date table is a representation of dates and the associated valeus as so you can filter against and use the columns in place of dates values from your fact table.

Here is a great template of a date table (https://www.sqlbi.com/articles/reference-date-table-in-dax-and-power-bi/); you can also google about for some simple Power Query to build you a super basic date table. Once you've added that in, join your fact and new date table with a relationship by the Date column in your fact table and the DateKey in the date table.

Hello you have to create a separate DateTable with contigous unique dates and relate the date columns.

There are dozens of posts how to do so. Here or here.

Total Sales YTD = TOTALYTD(sales_attributes1[Total Sales],DateTabel[Dates] )

4 years late but ... So I have found out If you already have a Column that has the dates lets call it {Date item was sold} or in your case if it lists the dates in a format such as {Friday, January 28,2022} then it the [TotalYTD] funtion won't work as a approrate value for the <Date> portion of the measurment.....and gives you the error you have seen.

The Date format I have seen the [TotalYTD] measure function like is MM/DD/YYYY once I Transformed my data in the {Date item was sold} from the date format of {Friday, January 28,2022} to {1/28/2022} then it worked like a charm!