Set Analysis using a date field

[#1]

Hi,

am trying to get a total sales value of all invoices for a particular promotional date. The set analysis I have written is as follows but does not seem to be working. Can anyone let me know what I am doing that is incorrect

many thanks

=sum({$<Invoice_Date = {$(=Promo_Start_Date)}>}[Sales_Value])

[#2]

try with date(Promo_Start_Date)