What is the name of the Dwarves’ New Year in J.R.R. Tolkien’s The Hobbit?

Durin’s Day is the Dwarves’ New Year in J.R.R. Tolkien’s The Hobbit.

In Tolkien’s calendar, Durin’s Day is the first day of the last moon of autumn when the sun and moon appear together in the sky. The date is not fixed according to an ordinary modern calendar, which makes it a distinctive calendrical event rather than simply a named holiday.

The day is important because Thorin Oakenshield’s company hopes to use it to enter the Lonely Mountain. A hidden door can be opened only at the correct time, when the last light of Durin’s Day reveals the keyhole. Readers sometimes confuse Durin’s Day with a general Dwarven festival, but in the story its crucial importance comes from this astronomical timing and the secret door’s mechanism.