“The first day of the last moon of Autumn” refers to the New Moon before the winter solstice, December 21. Thus, Durin’s Day is a “moveable feast,” like Easter, and could fall any time between late November and December 20, depending on the difference between the cycles of the Sun and Moon in any given year. The calendar reckoning needed to determine this exact date in advance requires a detailed understanding of astronomy. Thorin laments that he and his dwarves did not possess such knowledge:

“But this will not help us much, I fear, for it passes our skill in these days to guess when such a time will come again.”10

I wonder if Tolkien meant this as his own lament of modern culture, where such information “passes the skill” of most people, in his time and still in ours.

After much adventuring, Bilbo and the dwarves finally arrived along the side of the Lonely Mountain, in the proper season of Durin’s Day, as Thorin remarks that “tomorrow begins the last week of Autumn.”10 As they found themselves at the entrance to Erebor, it was Bilbo who providentially discovered the circumstances of Durin’s Day, as well as the clues to open the door:

As the sun turned west there was a gleam of yellow upon its far roof, as if the light caught the last pale leaves. Soon he saw the orange ball of the sun sinking towards the level of his eyes. He went to the opening and there pale and faint was a thin new moon above the rim of Earth.

The sun sank lower and lower, and their hopes fell. It sank into a belt of reddened cloud and disappeared. The dwarves groaned, but still Bilbo stood almost without moving. The little moon was dipping to the horizon. Evening was coming on. Then suddenly when their hope was lowest a red ray of the sun escaped like a finger through a rent in the cloud. A gleam of light came straight through the opening into the bay and fell on the smooth rock-face...

A hole appeared suddenly about three feet from the ground.11 [Just barely in the nick of time, Thorin was able to fit the key into the hole and open the door.]

The gleam went out, the sun sank, the moon was gone, and evening sprang into the sky.12

The reader can see from these instances that the key events of the story of The Hobbit turn closely upon astronomical appearances in the sky. A greater understanding of astronomy can enhance our appreciation of Tolkien’s wonderful story. There is also quite a bit of astronomy in The Lord of the Rings trilogy, but that’s another story .

Jay Ryan is a homeschooling father of five in Cleveland, Ohio. For more information about telling time by the Sun and Moon, check out Jay’s Moonfinder, a storybook for children, and Signs & Seasons, a homeschool astronomy curriculum. Both are available from many homeschool vendors, as well as Christianbook.com and www.ClassicalAstronomy.com.


1. Ch. 2, “Roast Mutton,” p. 42 (all citations are from the Ballantine paperback edition, 1973).

2. Ibid., p. 43.

3. Ch. 3 “A Short Rest,” p. 57.

4. Ibid., p. 59.

5. Ibid., p. 60.

6. Ibid., p. 61.

7. Ibid., p. 62.

8. Ibid.

9. Ibid.

10. Ch. 11, “On the Doorstep,” pp. 200–201.

11. Ibid.

12. Ibid.

Copyright, 2012. Used with permission. All rights reserved by author. Originally appeared in The Old Schoolhouse® Magazine, the family education magazine, December 2012. Read the magazine free at www.TOSMagazine.com or read it on the go and download the free apps at www.TOSApps.com to read the magazine on your mobile devices.