Default Schedule in Workfront - Company Time Off?

I've added company days off to our default schedule, but there is nothing stopping users from assigning work to be done on days the company has off.

For instance - we are closed tomorrow and Wednesday, but I am able to change planned completion dates to those dates without so much as a warning. Is this normal? Is there a way to show that the company is closed on these days when assigning out tasks?

Any help/insight would be greatly appreciated!