It's the fifth consecutive year the U.S. Open men's title match has been played a day later than planned.
The WTA final was shifted from Saturday to Sunday because of the weather, the fourth time since 2008 the women's event went long, too.
Murray is one of only two men to lose each of his first four major finals - his coach, Ivan Lendl, is the other - and he'll try to avoid dropping to 0-5.
He'll also try to become the first British man since Fred Perry in 1936 to win any of tennis' four most important tournaments.
Djokovic leads the head-to-head series against Murray 8-6 but lost their most recent matchup in the semifinals of the London Games.
The loss dropped Ferrer to 0-4 in Grand Slam semifinals, with another of those defeats also coming against Djokovic at the U.S. Open, back in 2007.
Djokovic was playing in his 10th consecutive Grand Slam semifinal, equaling Rod Laver and Lendl for the second-longest streak behind Roger Federer's record of 23.
In earning his tour-leading 60th match win of 2012, Djokovic also moved a step closer to being able to say he's had the best season.