i would start the registration process now. that way you can get your registration number as soon as possible and then think a bit about the exact date you want and where you want to take it depending on what your school has to say in those workshops.
just an idea since it takes a couple of weeks between wehn you pay for your test and when they allow you to pick a date, since you have to print out some forms and get a picture and official seal from your school administration.