George Day was born on 10 February 1891 in Welwyn, Herts, the son of Thomas and Emma Day, and baptised there on 7 June 1891. On the 1901 Census the family were living in White Hill, Welwyn where his father was a farm labourer.
They remained in Welwyn in 1911 and he was living with his mother and brother James at Frythe Cottages, White Hill, Welwyn. George was working as a navvy in the brickmaking industry. His father was not listed with them.