A framed chromolithograph by SPY (Sir Leslie Ward) picturing The Hon. Sir John Charles Frederick Sigismund Day a High Court Judge and art collector.

One of the first Roman Catholic judges to be appointed to the English bench since the Reformation, he was called to the bench in 1882. Well known for sentencing criminals to lashes, in his latter years, he would sometimes listen intently to cases with his eyes closed,  opening an eye suddenly if something significant were said, a mannerism which was jokingly referred to as "the peep of Day".

He sat on the Parnell Commission, a judicial inquiry into allegations of crimes by Irish parliamentarian Charles Stewart Parnell which resulted in his acquittal and vindication. At the time it was said that it was on his insistence that Richard Pigott was put into the witness box and his forged letters, implicating Parnell in the Pheonix Park murders of 1882 exposed as fraudulent.

He retired from the High Court of Justice in 1901, when he was granted an annuity of £3,500. In March the following year he was appointed to the Privy council. His portrait hangs in the Royal Courts of Justice.