Vivinavi

Private sale of a car and transfer of title

I am planning to return to Japan at the end of this month.
We are leaving Hawaii on July 31st, and have given our car to an acquaintance who will be living in Hawaii next month.

So my question is about registration.
We are giving up our car on July 31st
The acquaintance will enter Hawaii on August 14th.

As far as I can find out, the person who transfers the car will take the paperwork for the name change to Satellite City Hall, but there is an interval of 2 weeks from July 31 to August 14.
Is it OK if there is an interval between July 31 and August 14? ？
Do we only need to sign the documents or do we need to fill in the dates?

Thank you very much.