I teleworked the workweek before exam day. Three layers of management wanted me to study during official time as part of an approved professional development program. It really helped me do the last bits of studying and get into a good mindset for the exam.
I still did the minimum amount of normal work to "keep the lights on" through Monday. I did more normal work that Thursday than I did the other days and, in retrospect, it was a useful distraction from studying too hard. As mentioned above: I hit peak preparedness on Wednesday; Thursday was better spent getting in the right mindset.
I'd recommend taking the day off if your boss isn't as accommodating though.