Although this question has already asked about the different times for traveling to Rivendell from the Shire, it did not address the duration of the return journey from Rivendell to the Shire that occurred near the end of The Return of the King.
Chapter VII of Book VI specified Gandalf, Frodo, Sam, Merry, and Pippin crossed the Ford of Bruinen on "the sixth of October"; and the following chapter indicated the hobbits were in the Shire by "the first of November." Therefore, it presumably took approximately twenty-six days to travel from Rivendell to the Shire. However, this is less time than it took to travel in the opposite direction from the Shire to Rivendell.
Since Frodo, Sam, Merry, and Pippin walked to Rivendell in The Fellowship of the Ring but rode back to the Shire in The Return of the King, one might expect that their return trip would take less time; nevertheless, the time it took for them to return appears somewhat incongruous because in The Hobbit Gandalf, the dwarves, and Bilbo took about thirty-eight days to ride to Rivendell. Moreover, during the return journey, Gandalf told Mr. Butterbur, "We have been taking things easy," so it does not seem as if they were just riding faster when traveling back to the Shire than they were riding in The Hobbit.
Therefore, why did it take less time to travel from Rivendell to the Shire than to travel from the Shire to Rivendell?