Have you tried just getting the cheap rotating bezel watch JY recommends? I tried that out first, had no issues, and now can't imagine putting any extra thought into time keeping.
I had that Casio watch linked above, and my proctor confiscated it. I would recommend just buying a no-frills watch with no date display and no rotating bezel.
You should use the watch you have been using during your prep. The casio watch with the rotating bevel is the one I have used on my previous test and will use on Saturday.