E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
A non-business day. A law phrase, meaning a day when the courts do not sit, as on Sundays; the Purification, in Hilary term; the Ascension, in Easter term; St. John the Baptist, in Trinity term; and All Saints, with All Souls, in Michaelmas term. A contracted form of Dies non juridicus, a non-judicial day.