I think the point is to prevent people from using bid-bots after 3.5 days. Go ahead and self-vote your own post, just don't use your own bid-bot to upvote your post/comment.
His algorithm isn't looking for people that are upvoting things older than 3.5 days, it has a parameter of the bid-bots that are upvoting posts older than 3.5 days.
RE: GrumpyCat Weekly Report Thursday 05 April 2018