Middle Earth Calendar

[Otaku-sempai]

From The Hobbit we know that the Unexpected Party occurs on Wednesday ("Gandalf Tea Wednesday"), and that the previous Thursday was the 21st of April ("And Thrain your father went away on the twenty-first of April, a hundred years ago last Thursday..." Thus, April 21 of that year was a Thursday (which does not match with Shire Reckoning in LR, meaning the days of the week have probably been translated for us). That year was, according to the Tale of Years, T.A. 2941, or S.R. 1341.

Gandalf seems to have miscalculated here. Either Thrain disappeared on a Friday, April 21, or he vanished on a Thursday, April 20. Perhaps Gandalf was still trying to adjust his thinking for the Shire-reform calendar, which removed the week-day names from Midyear's Day and Overlithe, providing each day of the year with an unchanging week-day name (quoting from Foster's, The Complete Guide to Middle-earth).