The brisket is fairly small; 6 hours should be on the long side, may be more like 5, perhaps even as short as 4.5 hours. Watch it (not looking, I mean) carefully. When the temps get over 200 on it start checking for tenderness if you can. If not, just remove it at about 5.25 hours, have or put it in foil, wrap 'er up in a towel and set it in a cooler (used as a warmer) until 6pm.
So, you may be taking this off around 3:15 or 3:30, give or take. No worry. Glad it's done earlier than later...
You're going awesome!
Hance - Lake Dogs Cooking Team - MiM/MBN/GBA CBJ and comp cook
Lake Sinclair, GA (strategically about an hour from everywhere)