using the Format on a datetime gives error for not using max, count or sum

[ToNo87]

Hi,

I have the following DAX measure Year-Month-Setup = FORMAT('Setup'[EventTime], "YYYY-MM") the EventTime is in a DateTime Format, I can have multiple entires on a day. I want to make a reference to this by creating a new measure that just gives me the YYYY and MM so I can add in the one of my graphs to split the axis.

This is the error I am getting:

A single value for column 'EventTime' in table 'Setup' cannot be determined. This can happen when a measure formula refers to a column that contains many values without specifying an aggregation such as min, max, count, or sum to get a single result.

[KHorseman]

You're adding this as a measure, which means you have to have some kind of aggregation. FORMAT just formats a single result. You're giving it a column reference, which is not a single result. You'll need to nest something inside that format to get a single result. FORMAT(MIN('Setup'[EventTime]), "YYY-MM") or something like that.

[ToNo87 · Accepted solution]

Yes, that I can understand, however doing min or max will only give me one value, I can have multiple months of data?

EDIT: I changed it to a column and it solved the problem.