How do I create a realistic wedding photography timeline

Account for getting ready photos realistically
Allow 45 minutes to an hour for getting-ready coverage if you want detailed shots of hair, makeup, details, and people together. If your venue requires setup time anyway, the photographer can shoot while that happens. Don't overpack this time; 30 minutes of getting-ready photos is still plenty if that's all you want.
Leave breathing room for family and portraits
Family photos typically need 20-30 minutes depending on group size. Add another 30 minutes for couple portraits. If you're doing a first look, add 15 minutes. Build in a 10-minute buffer between major transitions so the photographer can move and doesn't feel rushed.
Reception timing needs flexibility
Cake cutting, first dance, and toasts don't all happen at fixed times. Work with your wedding planner or venue coordinator to confirm rough timing. If cocktail hour is unpredictable, tell your photographer to expect flexibility there. Overall, your photographer needs to know your approximate schedule, but exact timing shifts won't ruin the day as long as no major events are skipped.