The majority of the approach to the summit takes place in darkness because most summit bids begin from high camp at around 2300 to 0100, with the actual start time typically depending on the guide’s evaluation of the group’s performance during the previous several days.
Some climbers like to schedule their summit attempt with the full moon for scenic and atmospheric reasons, as well as to maximize the amount of light available when ascending.
The moon’s position in the sky as you approach the summit from high camp should be able to be seen in advance of the climb, rather than just choosing the closest convenient full moon date.
The following tool can be used in to achieve this. You can enter the dates of your intended climb, check the moon’s phase, and use a simple slider to see the moon’s position and elevation in the sky as you advance through summit night.
Some people don’t like climbing at night for two main reasons: it’s colder and you can’t see as well. A third factor that applies to kids is that it can be challenging for them to stay awake when it’s dark.
A new moon is actually much better for viewing stars, so many astronomy enthusiasts will try to time their summit bid with the time when the weather will be clearest and the night will be darkest. However, not everyone making a nighttime summit bid will find it preferable to climb on a full moon.