Sidney was born on 1 Nov 1913 in Lambeth, London south of the Thames. The exact date comes from the 1939 Registration of England and Wales, but is confirmed by the registration in 1913. 
Start of Second World War
When the nation was registered for I.D. cards at the start of WW2, Charles and Florence are still alive and active, though into their sixties. With them are two of their children, Sidney born 1913 and Violet born 1918, soon to marry Cecil Bate.
Marriage 1940 Croydon
Early in 1940 Violet Hunt married Cecil Bate in Croydon.
↑ freebmd Births Dec 1913
HUNT SIDNEY W mother-DYE @@Lambeth 1d 849
↑1939 Registration of England and Wales
RELATION TO HEAD NAME BIRTH MARITAL STATUS OCCUPATION
Head Charles J Hunt Sep 27 1876 Married Jobbing Gardener
Wife (implied) Florence J S Hunt Jan 7 1880 Married Unpaid Domestic Duties
Possible relative (implied) Sidney W Hunt Nov 1 1913 Single General Labourer
Possible relative (implied) Violet R Bate (Hunt) July 31 1918
↑ freebmd Marriages Mar 1940
Bate Cecil married Hunt @@ Croydon 2a 2052
Hunt Violet R Married Bate @@ Croydon 2a 2052