In 'Interstellar', what is the name of the planet with extreme time dilation near Gargantua?

In “Interstellar,” the planet with extreme time dilation near Gargantua is Miller’s planet. It is one of three potentially habitable worlds identified near the supermassive black hole.

The planet’s proximity to Gargantua creates an enormous difference between local time and time passing farther away. The film establishes that roughly one hour on Miller’s planet corresponds to seven years for observers elsewhere. This effect is an example of gravitational time dilation, a consequence of Einstein’s general theory of relativity: clocks run more slowly in stronger gravitational fields.

Cooper, Amelia Brand and Doyle land there after traveling through the wormhole near Saturn. They find a shallow, ocean-covered world, but the apparent landscape is dangerous: the planet’s “waves” are gigantic walls of water caused by its orbital environment. Miller’s probe has already arrived, but the crew discovers that the planet’s conditions are not what the earlier signal suggested.

Miller’s planet is often confused with Mann’s planet or Edmunds’ planet. Mann’s world is a frozen, deceptive refuge, while Edmunds’ planet is the destination where Brand eventually begins establishing a human colony. Miller’s planet is the one most directly associated with extreme time loss.