if with now()

Good Morning

I am trying to filter a dashboard to show only the last 30 days and yesterday numbers.

I had read that this is only possible creating a column with true/false using the "if" formula.

I am using the formula

if[Data]=NOW()-1 then true else false

but I get the error "Expression error: The name 'NOW' wasn't recognized. Make sure it's spelled correctly."

What I am doing wrong? I look allover and can not find the solution.

Thanks