Here's my heretical timeline. It doesn't fit with consensus, but it's based on what I know about Rocky Mountain weather and about sheep. (Mountain weather I know from working outside in a lot of different places and a lot of different elevations; sheep I know indirectly, by seeing places where they've grazed.)
The constraints I use are:
- I don't think they could realistically have taken the sheep into the mountains before mid-May. The snow stays late in the mountains, especially at high elevations (like near treeline), in the shade, and on north-facing slopes. (See also the description of the trail conditions during the May, 1983 camping trip in the short story.) There isn't much snow on the ground when they bring up the sheep during the movie, and the first pasture is above treeline.
- I don't think they would have moved the sheep to a fresh pasture before the beginning of July. Sheep will graze down to bare rock if you let them; presumably they moved the sheep because there wasn't much grass left for them to eat. And they only moved the sheep once. So I think the sheep-moving must have happened sometime near the mid-point of their expected summer. (Actually, before I saw the movie, I figured they moved the sheep around mid-July, but that doesn't fit with the moon phases and with things that must have happened before and after the first tent scene.)
- At least a month passes between their arrival on the mountain and the first tent scene. (Two full moons.)
- Dates of full moons in 1963: May 8, June 7, July 6, August 5
- The hail storm/Chilean sheep episode happens in early August in the story, and there's nothing in the movie to contradict that date, as far as I can tell.
- They come down from the mountain in mid-August (movie) (in the story, the first snow comes August 13, but Aguirre doesn't tell them to come down for another week). They expected to be on the mountain until mid-September.
So... proposed timeline:
- 1st week in June: bring sheep to the mountain.
- June 7: Jack looks at Ennis's camp. (This is a Friday/supply day, by the way.)
- 2nd week in June: "no more beans"
- June 14: the bear incident
- sometime between June 14 and July 1: job switch
- week of July 1: move camp
- July 6: first tent scene
- July 7: second tent scene
- sometime between July 14 and July 31: Aguirre sees the "happy tussle"
- 1st week in August: hailstorm, Chilean sheep
- August 13 or thereabouts: bring the sheep down.
(Hey! I'm letting them have five weeks of bliss! Given that I tend toward the most depressing interpretations of everything, I think that's pretty generous of me.
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