If there is one thing people remember from Cedar Breaks, it is the evening. The amphitheater faces west, so the low sun lights the hoodoos from the side for an hour, then drops behind the ranges beyond Cedar City and the whole sky goes orange over a bowl of rock that has just gone dark. At 10,000 feet, with nothing between you and the horizon, the colors are stronger than anywhere lower, and the show runs about fifty minutes from the first glow to the last light.
Then the second act. Cedar Breaks has been an International Dark Sky Park since 2017, and on Friday and Saturday evenings from June through September, June through September rangers set up telescopes at Point Supreme for a free Night Sky Tour that starts at 8:30 p.m. and runs to about 10:30 p.m.. You do not need the program to see the Milky Way; you need a clear night, a dark moon, and forty minutes for your eyes to adjust. This page gives you the sunset time for any date in the season, the tour nights when the moon stays out of the way, and the practical bits: where to park, when, and how cold it gets.
The whole evening, sunset to stars, takes two to three hours from arrival to departure, and you are 25 minutes from the inn at the end of it. That is the advantage of staying in Duck Creek Village rather than Cedar City or the parks: you can stay for the last telescope and still be in bed by eleven.