Peter Day was the second son of Olive Marion (nee Woodford) Day and Alan Percival Day. He spent his childhood in Pukekohe.

Married Edith Norma Tollerud (Canada) 9 July 1945.

"Alan Edward Woodford Day (Peter Day) was born in Pukekohe, Auckland, New Zealand, on 21 October 1920. A teacher by profession, he enlisted in 1940 and did his initial pilot training in New Zealand and later in Canada under the Empire Air Training Scheme (also known as the British Commonwealth Air Training Plan) graduating as a pilot-sergeant. In September, 1942, he was assigned to the North African campaign with 450 Squadron and was stationed first near Benghazi and later Tripoli. In March, 1944, he was posted to Corsica with 253 Squadron, and then on to Italy where he flew regular missions over Germany and Yugoslavia. On 7 August 1944 he was shot down over Croatia and taken a prisoner of war, eventually ending up at Stalag Luft III in Sagan and later Luckenwald, where he remained until being liberated in May, 1945. After the war he settled in New Zealand with his wife Edith, also a teacher, and together they taught for several years in Waiharara before moving to Canada in 1951. Peter Day died on 7 April 1982, and Edith exactly one month later on 7 May." - Banks, Sylvia. Papers relating to World War II Pilot Officer Alan Edward Woodford ('Peter') Day. Auckland War Memorial Museum Library. MS-2005/33. AWMM