FAFSA for wrong year?

I have NOT filled in any of my FAFSA information or submitted any information (aside from making an account), but
I registered too early for the 2016-17 school year (which opens Jan. 1st).
Do I just need to let January 1st come and then fill in the appropriate information after that date and submit? It doesn’t matter that I opened my account for the 2015-16 year, does it?

Yes