if anyone whose state board is Arizona just helps me out.
My 18 month period for my first exam is going to expire on 8/7/2019. I want to know what's the last date by which I can sit for my remaining exam's?
Is it ok if I sit on 8/6/2019? The result will be announced on 8/22/2019 after my credit expiration date.
So in that case, I would get to know my result on 22nd August and if I cleared my exam will my first exam credit expire or not?
Yes, sitting on 8/6 should be fine, even though you won't know the results until weeks later. It is similar to not knowing your 18 month window had started until you received your results. The important date is when you sit. I would contact the Arizona BOA to verify (I'm not in AZ).
I am waiting on my final exam score and it is set to be released AFTER my first credit expires. Will I lose my exam credit?
As long as you TAKE your final exam section BEFORE your first exam credit expires and when you receive your score it is passing, then you would not lose that first exam credit. All expiration times are set on Central Standard Time and are not calculated by your exam appointment time. If your first credit expires on January 31st, the latest you would want to take your final section would be January 30th.