How to use RECALL best? Date of the GMAT exam selection.
The timing of your GMAT examination is very important. No one knows when ETS will change the GMAT exam question bank, howerver, you can check the historical timing when ETS changed the GMAT exam question bank and select your GMAT exam date according to the interval. Normally 7-10 days after the date of question bank switch is considerable and you should have your own judgement on the GMAT exam date selection.