The grid language is the key.

Every other major airline (except JetBlue go figure) has DTZ. But, they effectively can't because the grid won't allow it. Requiring the month to start 75% green forces the company to adequetly staff the airline. This creates a bunch of positive effects regarding sched flexibility, ability to earn extra if you want, take time off if you want, and actually decent trips end up in open time b/c it's so easy to drop/pickup stuff. The grid rules must survive into the JCBA. Any contract without them is a NO vote from me and I might even quit over it.