DelegateDecompiler: Can't get DelegateDecompiler to play with DateTime

I absolutely love the concept, but I can’t get it to work with comparing DateTimes, something that I need to do a lot.

I’ve tried

[Computed]
public bool IsOverdue
{
   return this.FinishedAt.HasValue && this.FinishedAt.Value < DateTime.Now.AddDays(-1);
}

but it throws

LINQ to Entities does not recognize the method ‘System.DateTime AddDays(Double)’ method, and this method cannot be translated into a store expression.

I’ve tried using DbFunctions:

[Computed]
public bool IsOverdue
{
   return this.FinishedAt.HasValue && this.FinishedAt.Value < DbFunctions.AddDays(DateTime.Now, -1)
}

But it throws

Unable to cast object of type ‘System.Reflection.RuntimeConstructorInfo’ to type ‘System.Reflection.MethodInfo’.

Is there any way I can get a property like this to work, or am I out of luck?