See also The real hero tunnellers of World War One who inspired BBC's Birdsong, www.mirror.co.uk, 21 January 2012 (online), access date 6 July 2015, where the date of the detonation is given with 22 October 1915.
nztunnellers.com
Anthony Byledbal, "New Zealand Tunnelling Company: Chronology" (onlineArchived 6 July 2015 at the Wayback Machine), access date 5 July 2015