No, the "Settle" option is only shown once the "This event will pay out after" date has been reached. If you want to settle a bet before that time, edit it and change the date. Presumably, however, one wouldn't settle an event until the result is known, so it makes sense to set the "This event will pay out after " to that time in the first place. It defaults to being the same as the "accept bets until" date/time, which should be before the result is known.