Thank you for your interest in FileMaker Certification. I recommend that you take the FileMaker 14 exam as soon as you can. It will be retired when we release the FileMaker 16 exam. I cannot give an exact date, but it's getting close (definitely before DevCon).
And good luck on the exam.
Take is soon. The test for 13 was only available to schedule for one day after the test for 15 was released.
Thank you both for your wise responses. I suspected that the "close" was - well - close. Shifting to high gear.....