At least I don't have that. Each kid ends at 18 or graduated HS, whichever is later, but cannot extend beyond the 19th birthday.
The one that grates on me is the alimony. That has no defined end date. I was smart enough to get a clause put in that if she cohabitates for 12 months or longer (w/o getting married) it ends, and it obviously ends if she gets remarried. But it's been 10 years and she seems to be showing no signs of doing either--and at her age the options are likely not quite as plentiful as they might have been 10 years ago.
In retrospect, I should have gotten a clause put in that alimony can't go any further than the last child support payment. She probably would have agreed to it because with her ego and thinking she was hot shit, she would have thought there was NO chance she wouldn't be hooked up with someone obviously far better than me by now...