Professor having a test during the Test ban period between April 2nd to 9th.

Obviously I wouldn't want to make myself known to the prof in case he gets mad. Help/advice appreciated.

First, you should make sure the test applies under the ban:
http://www.mcmaster.ca/policy/Studen...essmentBan.pdf

Second, you should know that profs can get exemptions. Assignments that are replacing a final exam (e.g. final lab report or project in a course that does not have a final exam) are also allowed.

You could probably ask the academic advisors for your faculty (or the faculty that the course/prof belongs to). If you phrase it properly, you should also be able to ask the prof (at the very least, ask if they got an exemption).