It’s getting late, estimating night time is a helpful survival and adventurer trick
Telling time in the wilderness is a great boy scout / adventurer trick that comes in very handy. Whether backpacking, camping, lost, estimating when you should be back at your camp… there will come a time when you don’t have a watch (or do have a watch and don’t know when the sun is supposed to set) and can use this trick.
Placing your hand perpendicular to the ground with fingers touching sides, just under the sun, each finger spanning towards the horizon equals fifteen minutes.
This pin I found on Pinterest couldn’t explain it better: