Move templates in settings for the remaining year

As an elementary school teacher, I often find myself moving subjects around during the year. I love how I can move the templates around and that works great for a day here or there. But when I need to move the template around more a longer period of time, it moves it for time in the year I've already taught. I want something that allows me to move templates around from a certain point forward while keeping what's previously been done in the same location.