Sounds like you're learning the curve, it's done when it's done. Every piece of meat is different and it's hard to time them sometimes. If you need to serve at a certain time start early and then place the meat in a cooler to keep it hot for serving.
"People who drink light 'beer' don't like the taste of beer; they just like to pee alot."
GRIM REAPER SMOKERS - "BBQ To Die For"™ Under the "LENIENT" direction of Pit Master Tim.
22.5 OTG, 18.5 OTS, 18.5 WSM, Chargriller Duo with optional side fire box.
"Founders Club" Operation BBQ Relief.