Question: When was English football manager, who managed West Ham United from May 2011 to May 2015, known as "Big Sam" born?

<P0-S0> London football team, West Ham United have had only fifteen permanent managers in their history and an additional three caretaker managers. <P0-S1>  Up until 1989 the club had only had five different managers. <P0-S2>  Before the appointment of Gianfranco Zola in 2008 the club never had an overseas manager, with the only non-Englishman being the Scot, Lou Macari. <P0-S3>  The current manager is Slaven Bilić who was appointed in June 2015. <P0-S4>  The most recent manager before that was Sam Allardyce who was appointed in May 2011 and left the club in May 2015. <P0-S5>  Numerous former West Ham players have taken on temporary managerial roles at the club, between permanent managers. <P0-S6>  Ronnie Boyce briefly took the reins, in February 1990, between Macari's resignation and the appointment of Billy Bonds. <P0-S7>  Former Hammer's player and board member Trevor Brooking was briefly in charge during two separate spells as caretaker manager in 2003, first during the illness of Glenn Roeder and again between Roeder's sacking and the appointment of Alan Pardew. <P0-S8>  Former player Kevin Keen has been caretaker manager twice; immediately prior to Gianfranco Zola's appointment in 2008 and after the sacking of Avram Grant in 2011. <SEP> <P1-S0> Frederick David "Freddie" Sears (born 27 November 1989) is an English professional footballer who plays as a forward for Ipswich Town. <P1-S1>  He started his career with his local club West Ham United at the age of eleven, progressing through the West Ham United Academy. <P1-S2>  He made a scoring first-team debut in March 2008 when he netted the winner against Blackburn Rovers after coming on as a second-half substitute. <P1-S3>  Sears made over 50 first-team appearances for West Ham, but never held down a regular starting position. <SEP> <P2-S0> Samuel Allardyce ( ; born 19 October 1954), known as "Big Sam", is an English football manager and former professional player, who most recently managed Crystal Palace from December 2016 to May 2017. <SEP> <P3-S0> Gary Strodder (born 1 April 1965 in Cleckheaton, West Yorkshire) was a centre half who played for West Ham United for four seasons, making 71 starts in total with a further eight appearances as substitute. <P3-S1>  His two goals were both scored against South Coast opposition, Portsmouth and Bournemouth. <P3-S2>  He joined in March 1987 from Lincoln City. <P3-S3>  Gary is probably best remembered by West Ham fans for being a member of the team hammered 6-0 in the League Cup Semi Final first leg at Oldham Athletic. <P3-S4>  This proved to be his penultimate game in the famous Claret and Blue shirt. <P3-S5>  In addition to West Ham, Gary also played for Notts County, Rotherham United, West Bromwich Albion, Hartlepool United and Lincoln City. <P3-S6>  His greatest moment probably came in helping West Brom to promotion via the playoff final at Wembley Stadium in a team managed by Argentinian and Tottenham Hotspur legend Ossie Ardiles (1993). <P3-S7>  In May 1985 he was to witness a nightmare when 56 spectators were killed in a horrendous stand fire while playing for Lincoln against Bradford City.