Alpenglow: when the peaks turn red
Short answer: High summits see the sun minutes before sunrise and after sunset in the valley, and glow red, orange and gold while everything below is in shade. The window is short: about 20 to 40 minutes. Pick a peak to see the exact time on your date and when to be in place.
Matterhorn
Today: first light 07:18
Torres del Paine (the three towers)
Today: first light 05:58
Mount Fitz Roy
Today: first light 06:03
Moraine Lake (Valley of the Ten Peaks)
Today: first light 08:44
Aoraki / Mount Cook
Today: first light 06:06
Half Dome
Today: last light 17:03
Jungfrau (from Interlaken)
Today: last light 17:19
Rosengarten / Catinaccio (Dolomites)
Today: last light 16:55
Mount Rainier
Today: first light 06:47
Mount Fuji at dawn (Red Fuji)
Today: first light 06:05
Kilimanjaro (from Amboseli)
Today: first light 06:00
Everest (from Kala Patthar)
Today: last light 17:17
How we calculate it
A summit high above its surroundings looks down on its own horizon, so it sees the sun before anything below it. For each date we find the moment the sun's upper edge clears the skyline as seen from the summit (allowing for the dip of the horizon, refraction and higher ridges nearby). The red, then orange, then gold glow lasts until the sun is about 5° higher. Expect the real moment within about 5 minutes.
For the sun setting exactly on Mount Fuji's summit, see the Diamond Fuji calendar.