The dates for 2017 are officially out- March 24th & 25th, if you would like to add them to next year's calendar. It is typically a two day choir festival, although show choirs usually perform only on the second day.
Schedule is posted. This looks to be a really good competition! I'm not totally sure what the difference is between Tier I and Tier II as it isn't described on their website, but it looks like it could be school size. It's overall an interesting mixture of West Virginia, Maryland, and Virginia choirs.
There aren't finals. Middle school show choir awards should happen around 12:30 PM and the high school awards follow Martinburg's "Good Times" exhibition performance which is at 10:20 PM.