Hi tanickle,
First, do not worry too much about your GMAT test date. Most candidates do not know how their GMAT scores are reviewed by admissions teams.
When you apply to business school, your GMAT score is self-reported on your application. What this means is that you report your highest score, and it is then verified when you are accepted. Admissions teams will only focus on your highest score.
If you take the GMAT test and do not receive the score you are hoping for, you can always take the test again. In fact, a lot of people recommend expecting to take the test at least twice. Retaking the test is not the worst thing in the world.
If you are looking for GMAT tips, MBA.com has 2 official practice exams. We also have free GMAT advice and information here:
https://www.stacyblackman.com/tag/gmat/Hope this was of help.
Cheers,
Conrad and the
Stacy Blackman Team