Around the same as every year. The testing calendar is usually released in mid-late September, and registration usually opens mid-lat October.
-the 2018 test calendar was released on Sept 21
-pre-registration for Jan-Jun 2018 testing dates was made available starting Oct 12, 10AM EST
-test registration for Jan-Jun 2018 testing dates opened Oct 18, 7:30AM EST
-test registration for Jul-Sept 2018 testing dates opened Feb 7, 2018, 7:40AM EST