There's no change to the voter registration - you can still check the box after the nominations/votes start. For voting purposes, you can do the agreement any time. However, you do want to check eligibility before tomorrow if you have videos participating. And you won't be able to nominate/vote without checking the agreement, so might as well do it now!
"...for her, I'm obsolete and unhealthy; but I'm wealthy enough - allow me, lady, to look in sorrow upon this world."