In The Hobbit, what mistakes do the dwarves make about Durin's Day? What does this tell you about them?

After much searching, the dwarves and Bilbo find a narrow shelf on the western side of the Lonely Mountain that leads to a flat smooth surface. They recognize it at once as being the secret entrance, but they have forgotten the translation provided to them by Elrond that the passage can only be opened with the key when the last light of Durin's Day strikes the door. The dwarves try to force the door open...

After much searching, the dwarves and Bilbo find a narrow shelf on the western side of the Lonely Mountain that leads to a flat smooth surface. They recognize it at once as being the secret entrance, but they have forgotten the translation provided to them by Elrond that the passage can only be opened with the key when the last light of Durin's Day strikes the door. The dwarves try to force the door open and to break the rock from which it was made, but their weapons prove to be useless against it. No amount of pushing or prying causes it to move in any way. The dwarves become discouraged, giving up on the door. It is only Biblo who eventually remembers the translation, and as the sun sets on Durin's Day a ray of light strikes the door, revealing the keyhole that can be used to open it.

This series of events speaks of the general character of the dwarves in the mythology of Tolkien. The dwarves are talented craftsmen and have a great knowledge of the value of things, but they are also rather blunt and stubborn. It is only the patient thoughtfulness of the hobbit that allows them to gain entry to the mountain and continue on their quest.