The turkey takes three and a half hours. The casserole needs the oven the turkey is in. The gravy needs drippings that don't exist yet. And someone just asked when dinner is. Working backward from your serve time sequences the oven handoffs and the resting window so every dish converges instead of colliding.
A Thanksgiving kitchen is a scheduling problem disguised as cooking. You have one oven, a turkey that monopolizes it for hours, sides that need it the moment the turkey comes out, and a serve time that doesn't move. Most recipes give you cook times. None of them tell you when to start relative to everything else. That's the gap where the last-hour scramble lives.
The turkey needs to rest before you carve it. That 30-minute resting window is when the oven is finally free. Ready Time works backward from your serve time and slots the sides into that window. Casserole goes in while the turkey rests. Gravy starts from the drippings. Rolls warm in the last ten minutes. You follow the timeline instead of juggling it in your head.