I was trying to look for the possible date for taking the CISSP test (so that I can prepare myself in advance), but I couldn't find such information. Could anyone give some suggestions?
Thank you so much!
testing isn't done by ISC2 itself but by a company called Pearson VUE.
You have to register with Person VUE, lookup the available testing centers and then select a date of your choice to do the test. The testing centers do offer the tests on a daily basis (or at least weekly) so no need to prepare for a specific date.
See https://www.isc2.org/Register-for-Exam for more information
Adding to what Wolfgang said:
Depending on your area, there can be several nearby testing centers to choice from. In my area, some are only open certain days a week, which can affect available dates.
Also, testing times fill up, so when you decide to schedule a date, most likely there won't be anything available in the coming month.
Once you've picked a date, while you can re-schedule, there are some limits, and a potential charge for doing so.