I have to admit, knowing you will be spending a hungry hungry day on the first if you don't attend the yard would be fabulous motivation.
I've decided to somewhat modify it for myself and start the same thing.
From now on, Fridays at my house will not feature any pre-packaged food, and the first of each month those over the age of 14 won't find food in my home that wasn't grown here or bartered for something grown here. Anyone under age 14 will be given the option to participate or not.
This Friday is the first of the month, and the first 1st after the Spring Equinox/Ostara/Holi...so that seems an appropriate day to start.