Schedules at all test centers fill up quickly. We strongly encourage examinees to complete their scheduling before May 31 of the calendar year in which they plan to test. Testing appointments are typically completely filled at least three to four months in advance. If you try to schedule after August 1, you may find that there are no available testing appointments through the end of the year unless there are cancellations.
More information is available in the Applying for the Test and Scheduling Your Test Date section of the Bulletin of Information.