Null value in calculated decimal column

[Anonymous]

I am new to PowerBI what I am trying to do now, is calculated the days between two dates but they may have nulls. So I made the column expression as the following:

Number of Days = if(ISBLANK([start_date]) || ISBLANK([end_date]),NULL,1*([end_date] -[start_date]))

I need this column to hold decimal numbers (I need the exact difference between the dates e.g. 1.457 days) so I changed the type to "Decimal Number" but it gives me the following error:

Operator or expression 'NULL' is not supported in this context.

I am very grateful for any contribution 

[v-yulgu-msft · Accepted solution]

Hi @Anonymous,

Please use BLANK() rather than NULL in DAX formula.

Number of Days = if(ISBLANK([start_date]) || ISBLANK([end_date]),BLANK(),1*([end_date] -[start_date]))

Best regards,

Yuliana Gu