“As a professional scholar of Medieval British and European literature, Tolkien was a knowledgeable explorer of a number of imaginary worlds - the middangeard (“The Middle-earth”) of Beowulf, the grim and brutal cosmos of The Völsunga Saga, the cold and bitter realm of the Eddas - and all of them worked their sway over his imagination, lodging there to ferment and bubble over into a new world, the Middle-earth of the hobbits.”

Randel Helms, Tolkien’s world. Houghton-Mifflin, 1974, page ix.

Durin's day falls when the last moon of Autumn and the first sun of Winter appear in the sky together. If you aren't sure when that is, click here to find out when you should be celebrating. 

Buge Sophus. Norrœn fornkvæði : islandsk samling af folkelige oldtidsdigte om Nordens guder og heroer almindelig kaldet Sæmundar Edda hins Fróða.

Christiania: P.T. Malling, 1867

From the library of William Morris’ Kelmscott House. Gift of Robert T. Meyer.

All names of the dwarves in J.R.R. Tolkien’s Legendarium come from Norse mythology, as does the name Gandalf. You can spot many of them in the fragment from the poem Völuspá, seen above (stanzas 9-15).

Fun fact: Did you know that in the original Hobbit  manuscript, “Gandalf” was the name of the character known now as Thorin, while Gandalf himself was called Bladorthin?

Björnsson, Stefán, and Peter Frederik Suhm. Hervararsaga ok Heidrekskongs. Hoc est Historia Hervöræ et regis Heidreki

Hafniæ: P. F. de Suhm, 1785.

Translated in English as The Saga of Hervör and King Heidrek, this legendary 13th-century saga is based on older Nordic/Germanic material. Among others, it tells the story of two dwarves, Dwalinn and Durin, who forge a magic sword called Tyrfing.

The first English translation, made by Christopher Tolkien, was published in 1960 as The saga of King Heidrek the Wise. (his translation of the above fragment is as follows)

From The Saga of King Heidrek the Wise
(translated by Christopher Tolkien)

…It chanced one day that King Svafrlami rode out hunting, and far on into the day he pursued a stag, without ever overtaking it before the time of sunset. By then he had ridden so deep into the forest that he scarcely knew which way to turn for home. At sunset he saw a great stone, and beside it two dwarfs. The king drew his graven sword over them, and with that sign held them outside the stone. They begged him to spare their lives, and Svafrlami asked them what their names were. One said he was called Durin, and the other, Dvalin. 

Svafrlami knew that these were the most skilful of all dwarfs, and he laid this charge upon them, that they should make a sword for him, the best their skill could devise; its hilts were to be of gold and its grip also, and they were to make its scabbard and baldrick of gold. He said that this sword must never fail and never rust, must bite into iron and stone as if into cloth, and that victory must always come to him who carried it in battles and single combats; this was the price of their lives. On the appointed day Svafrlami returned to the stone, and the dwarfs delivered over to him the sword; it was very beautiful. 

But when Dvalin stood in the doors of the stone he said, ‘ May your sword, Svafrlami, be the death of a man every time it is drawn, and with it may three of the most hateful deeds be done; may it also bring you your death! ’

Then Svafrlami struck at the dwarf with the sword, and the ridges of the blade were hidden in the stone; but the dwarf leapt back into it. Svafrlami kept the sword and called it Tyrfing; he bore it in battles and in single combats, and with it he slew the giant Thjazi…

Christopher Tolkien, The Saga of King Heidrek the Wise = Saga Heiðreks Konungs Ins Vitra, (London: Nelson, 1960), 68.