3 hour glucose test

My ob said don’t eat 8hours before I take the test , I last ate around 9pm today . I wanna go to do the test tomorrow as soon as the office opens at 7am. So does this mean I can’t eat anything after 12am or should I just stop right now bc I was gonna have a snack ... does the 8 hour before count when u go to sleep ? If I’m making any sense lol