Question: What is the birthdate of this Dutch retired international football player, who is the father of Daley Blind?

Context paragraphs:
Željko Vuković (footballer, born 1962): Željko Vuković (born 9 February 1962) is a retired international Croatian and Austrian football player.

Moisés Candelario: Moisés Antonio Candelario (born 10 October 1978 in Guayaquil) is a retired international football player from Ecuador.  He played as a defensive midfielder.

Joaquín Reyes (footballer): Joaquin Reyes Chávez (born 20 February 1978 in Torreón; birthdate alternatively shown as 13 August 1979) is a retired Mexican football player who last played for Celaya.

Danny Blind: Dirk Franciscus "Danny" Blind (] ; born 1 August 1961) is a Dutch retired international football player.  He played as a defender for Sparta Rotterdam, Ajax and the Netherlands national team.

Pier Tol: Kees "Pier" Tol (born 12 July 1958) is a Dutch retired international footballer who made over 300 professional appearances in the Dutch league, scoring over 100 goals.

Pirom Un-prasert: Pirom Un-Prasert (Thai: ภิรมย์ อั๋นประเสริฐ ) (born November 16, 1953) is a retired international football referee from Thailand.  He is best known for refereeing the 1997 FIFA Confederations Cup Final and two matches in the 1998 FIFA World Cup in France; the Norway-Morocco and Paraguay-Nigeria matches in the first round.  He also officiated at the 1995 FIFA Women's World Cup, the 1996 Olympic tournament in Atlanta, the 1996 AFC Asian Cup, and eight matches in 1998 World Cup qualifiers.

Otman Bakkal: Otman Bakkal (born 27 February 1985) is a Dutch retired international footballer who played as an attacking midfielder.

Manouchehr Nazari: Manouchehr Nazari is a retired international football referee, who has worked with FIFA and the AFC.  He is head of the Iranian Football Referees Committee.

Erik Nielsen (footballer): Erik Nielsen (born 12 December 1937 in Copenhagen, Denmark) is a former Danish international football player, and father of the former international football player, now manager, Kent Nielsen.

Daley Blind: Daley Blind (born 9 March 1990) is a Dutch professional footballer who plays as a defensive midfielder, left-back and centre-back for English club Manchester United and the Netherlands national team.  He is the son of former Ajax defender and former Netherlands national team manager Danny Blind.

Supporting paragraphs: Daley Blind Danny Blind
Answer: 1 August 1961