I Get an Error Every Time I Try to Use .getMonth()

I Get an Error Every Time I Try to Use .getMonth()

Why do I get this error:

Either the left side or the right side of a bolean expression must refer to a form/view field

When I try to use the following code in a "For each record" script:

HarvestDate.getMonth() == zoho.currentdate.getMonth()

The left side of this expression (HarvestDate) is clearly from my form.

I get the same error if I try to use .getYear()

Please enlighten me.