Question: What is the birthdate of this Slovenian football coach and former international player, who managed ND Črnuče in their golden years?
Context: Darko Milanič (born 18 December 1967) is a football head coach and retired Slovenian football defender.  He is currently a head coach of Maribor in the Slovenian PrvaLiga.  He is a former head coach of Austrian Bundesliga side Sturm Graz. Qu Shengqing (; Pinyin: "Qū Shèngqīng" born June 5, 1975) is a Chinese football coach and former international player.  As a player, he is well known for his time with Liaoning FC where he won the Golden Boot in the 1999 league season before joining Shanghai Shenhua and winning the 2003 league title with them.  He would also move abroad to A-League side Adelaide United before returning to China to end his career with lower sides Nanjing Yoyo and Shenyang Dongjin.  Since retiring he has moved into coaching where he is the current manager of the Guangzhou F.C. Reserve team. Edin Osmanović (born 20 May 1964) is a Slovenian-Bosnian UEFA Pro football coach who is currently the head coach of Slovenian team Fužinar.  He began his career in Rudar Trbovlje and later coached many clubs in the Slovenian PrvaLiga, the highest level in Slovenian football, including Celje, Gorica, Rudar Velenje, Korotan Prevalje, Dravograd, Aluminij, and Mura 05. Nogometno Društvo Črnuče, commonly referred to as ND Črnuče or simply Črnuče, is a Slovenian football club from the town of Črnuče, founded in 1971.  Their golden years came in the mid-1990s, when they were managed by Slovenian football legend Branko Oblak, who came to Črnuče as manager in 1994.  They have won the Slovenian Third League and finished in the third place in the 1995–96 Slovenian Second League, but then refused promotion.  They merged with nearby NK Factor in 1997 and the team moved to Factor's home ground in Ježica.  Črnuče then reestablished their own squad to play at domestic Črnuče Sports Park in lower divisions, but they never came higher than fourth level. Nogometni Klub Mura (English: Mura Football Club ), commonly referred to as NK Mura or simply Mura, was a Slovenian association football club based in Murska Sobota.  The club was founded on 16 August 1924 as one of the first clubs in the Prekmurje region.  Through its history Mura was widely considered one of the giants of Slovenian football and had one of the biggest fan bases in the country.  The club had its golden years in the 1990s when they managed to win the Slovenian Cup.  During this period they were also runners-up in the Slovenian first division twice and finalists in the Slovenian cup and Slovenian Supercup on one occasion. The 2011–12 season was the 52nd season in the history of NK Maribor and the club's 21st consecutive season in the Slovenian PrvaLiga since the league establishment in 1991.  The team participated in the Slovenian PrvaLiga, Slovenian Football Cup, UEFA Champions League, and UEFA Europa League.  The season covers the period from 1 June 2011 to 31 May 2012.  Darko Milanič was a head coach of the club. Janez Pišek was a Slovenian football manager and former player.  He played for AŠK Primorje most of his career and later managed various clubs in the Yugoslav Second League.  He became first professional Slovenian football coach and first president of Slovenian Football Coach Association in 1953.  After his death he received a Blodek plaque for life work in Slovenian football. Adrian Lam (born 25 August 1970 in Rabaul, Papua New Guinea) is a Papua New Guinean rugby league football coach and former international player.  He is the current head coach of Papua New Guinea.  As a player, he is a former Papua New Guinea international and Queensland State of Origin representative.  Lam moved from Papua New Guinea to Brisbane in the Australian state of Queensland at the age of 7 where he was raised. Branko Oblak (born 27 May 1947 in Ljubljana, PR Slovenia, FPR Yugoslavia) is a Slovenian football coach and former international player.  He usually played as an attacking midfielder or deep-lying playmaker. The 2012–13 season was the 53rd season in the history of NK Maribor and the club's 22nd consecutive season in the Slovenian PrvaLiga since the league establishment in 1991.  The team participated in the Slovenian PrvaLiga, Slovenian Football Cup, UEFA Champions League, and UEFA Europa League.  The season covers the period from 1 June 2012 to 31 May 2013.  Darko Milanič was a head coach of the club.
Answer: 27 May 1947