When I was 13, I worked at a family run Chinese restaurant as the dishwasher. I worked there until I graduated high school. Shortly after I started, I was often asked to help cook when they were busy. To start, I was put on the fryer which seemed pretty easy. I asked how long to keep the chicken in the fryer for the sweet and sour chicken. The answer: til they're done. I asked how will I know when they're done and was told: they'll be cooked. I thought he was being an a$$hole, but really, he was giving me the most truthful answer possible. After f-ing it up a few times (at first, when getting the hang of it, I always would cut a piece or two open to make sure they were done) I got the hang of it and understood that the only answer to how long to cook the chicken really is 'until it's done'.
Moral of the story, grow your plants til they're done. You'll know they're done when they look done. You may f-it up a couple of times and harvest a little early or a little late, but eventually you'll learn to find the sweet spot and you'll be able to do it time and again with absolute precision! And, contrary to poor outcomes of serving raw chicken, if you harvest too soon or too late, no one gets sick! Either way, you have some weed, so yay for that!