Normally the closing date should be after the event happens. Bets made later on have no influence on bets made earlier, so closing a week ahead of the expected resolution only ties up mana for no reason.

If you truly want to close the market a week before the event, that's fine, but I think most participants generally like to be able to trade. There is a real chance that the news breaks during the time this market would be closed, a few days before the event.

How does this resolve if there is no such announcement? Is that "Other" as well?