I’d suggest getting a few more on the list then picking one at random per week (starting Monday14th Sept) not necessary in order to keep people on there toes and to stop stock piling. date of photo/video to be presented when entered.
There was a ploughing competition at a farm near where I live (<5 mins drive) and it was held the day before the birthday challenge finished so if I’d been on the ball there was the possibility of a single very late entry. Unfortunately I only found out about it when browsing the local paper after the event (and after the competition finished). Not that it matters anyway, the guys that put in the effort deservedly won.