Newspaper article says ‘On Saturday’
Newspaper printed ‘Friday 6th Sept’
So Sat August 31st 1940 ?
And to be pedantic it actually says ‘Suburb’ of London not actually mentioning Dagenham. So could be anywhere, but due to ‘detail’ in story may be local!
Bingo!
31.8.40 Spitfire I X4271 603 Sqn Hereford Road, Wanstead, Essex P/O G. K. Gilroy
http://www.thesoutheastecho.co.uk/Pilots/Gilroy.htm