I'm trying to recreate the following ability but I can not correctly calculate the CD. "Once every 6 hours, an ankheg can spit a 30-foot line of acid. Creatures struck by this acid take 4d4 points of acid damage (Reflex DC 14 halves). The save DC is Constitution-based." I would like to get the creature's HD, divide them by two and add 10 plus constitution modifier. I used the following scripts: (getCasterHD()/2)+getConMod()+10. But the CD gives me 0 as a result.