We use 135 rules at NJA, 14 hour duty day not 12.

Yes the 14 hour clock starts ticking at least 1 hr prior to your airline departure, you get a brief by 1800 the night before your first duty day
Example
0900 show for a 1100 airline
14 hours clock starts ticking at 0900

Nice part is getting overtime (over 12 hours) while sitting in the terminal waiting for your flight home, new hires thats $40 an hour, and if your airline is late for any reason and you get in after midnight you get 2 extended days (3 days pay $940. for a new hire).