Default Value and Expression Minus 1 Day

[armyofdux]

So I am trying to setup a default value in the tbl design. The Following two fields are the two in question(StartDate & ReportDate). It already has relevant dates properly formatted in the StartDate Field. The ReportDate will always be the day before or minus 1 day from the Startdate. My question is that I can't seem to get the syntax right to make it work. Screenshot included.

[armyofdux]

So I have found it is just much easier to save an update query with DateAdd("d",-1,[StartDate])