Really, remove that box from there. As TMRD already said, It doesn't fit the criteria to be nominated.
Seriously.
Why don't you remove my Halo box and let the AC/DC box stay? Will that not even things out?
Considering how difficult it is to even remember the boxes that were posted from one year to the next, I see no issue with considering his box for the Award. It's certainly one of the best Music covers we've ever had on the site, and I really don't think one day will make a difference. If it was posted this week, or last December, I could see it, but one day? It really should stay in. It's difficult enough just remembering who SHOULD be nominated, much less worrying about a few hours difference.
So it's basically because it was off by one day. Seriously dude, this isn't like winning the nobel peace prize or something. It's just a fun competition to increase the morale of the box art community here. We're not even giving you a physical trophy or anything. Don't make this a big deal, and just take what you get.