Scholars have assumed that Day was born and raised in Dunwich, but there is no direct evidence that proves this claim.[6] He may have been in London by 1540, as his name is mentioned in a city deposition as being a former servant of the printer and physician Thomas Raynalde. In 1546, he was probably one of twenty men who were granted the freedom of the city by redemption to work for the Stringers' Company of London.[7]