E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
St. Johns Eve, St. Marks Eve, and Allhallow Even,
are times when poets say the forms of all such persons as are about to die in the ensuing twelve months make their solemn entry into the churches of their respective parishes. On these eves all sorts of goblins are about. Brand says, On the Eve of John the Baptists nativity bonfires are made to purify the air (vol. i. p. 305).