Question: When was Rupert von Trapp father born? 

Context paragraphs:
Hedwig von Trapp: Hedwig Maria Adolphine Gobertina von Trapp (28 July 1917 – 14 September 1972) was the fifth child of Georg von Trapp and his first wife, Agatha Whitehead von Trapp.  She was a member of the Trapp Family Singers, whose lives were the inspiration for the play and movie "The Sound of Music".  She was portrayed as the character "Brigitta".

Agathe von Trapp: Agathe Johanna Erwina Gobertina von Trapp (12 March 1913 – 28 December 2010) was the eldest daughter of Georg von Trapp and his first wife, Agatha Whitehead von Trapp.  She was also a member of the Trapp Family Singers, whose lives were the inspiration for the play and film "The Sound of Music".  She was portrayed as the character "Liesl".

Werner von Trapp: Werner Ritter von Trapp (21 December 1915 – 11 October 2007) was the second-oldest son of Georg von Trapp and his first wife, Agatha Whitehead von Trapp.  He was a member of the Trapp Family Singers, whose lives were the inspiration for the play and movie "The Sound of Music".  He was portrayed as the character "Kurt".

Maria von Trapp: Maria Augusta von Trapp (née Kutschera; 26 January 1905 – 28 March 1987), also known as Baroness von Trapp, was the stepmother and matriarch of the Trapp Family Singers.  She wrote "The Story of the Trapp Family Singers" which was published in 1949.  The story served as the inspiration for the 1956 West German film "The Trapp Family", which in turn inspired the Broadway musical "The Sound of Music" (1959) and the 1965 film of the same name.

Georg von Trapp: Corvette Captain Georg Johannes Ritter von Trapp (4 April 1880 – 30 May 1947), often incorrectly referred to as Baron (Freiherr) von Trapp, was an Austro-Hungarian Navy officer.  His naval exploits during World War I earned him numerous decorations, including the prestigious Military Order of Maria Theresa.  Under his command, the submarines SM "U-5" and SM "U-14" sank 13 Allied ships totaling about  gross register tons (GRT) .

Maria Franziska von Trapp: Maria Agatha Franziska Gobertina von Trapp (28 September 1914 – 18 February 2014) was the second-oldest daughter of Georg von Trapp and his first wife, Agatha Whitehead von Trapp.  She was a member of the Trapp Family Singers, whose lives inspired the musical and film "The Sound of Music".  She was portrayed as the character "Louisa".  She died at age 99, and was the last surviving sibling portrayed in the film.

The von Trapps: The von Trapps (formerly The von Trapp Children) is a musical group made up of Sofia, Melanie, Amanda and August (formerly Justin) von Trapp, descendants of the Trapp Family Singers.  They are the grandchildren of Werner von Trapp, who was portrayed as Kurt in "The Sound of Music", and the great-grandchildren of Georg Ritter von Trapp and his first wife Agathe Whitehead, and the step-great-grandchildren of Maria von Trapp, Georg's second wife.

Edelweiss (song): "Edelweiss" is a show tune from the 1959 Rodgers and Hammerstein musical "The Sound of Music".  It is named after the edelweiss, a white flower found high in the Alps "(Leontopodium alpinum)".  It was created for the 1959 Broadway production of "The Sound of Music" in the role originated by performer Theodore Bikel as a song for the character of Captain Georg Ludwig von Trapp.  In the musical, Captain von Trapp and his family sing this song during the concert near the end of Act II as a statement of Austrian patriotism in the face of the pressure put upon him to join the navy of Nazi Germany following the Anschluss.  It is also Captain von Trapp's subliminal goodbye to his beloved homeland, using the flower as a symbol of his loyalty to Austria.  In the 1965 film adaptation, the song is also sung by the Captain earlier in the film when he rediscovers music with his children.

Rupert von Trapp: Rupert Georg von Trapp, M.D. (1 November 1911 – 22 February 1992) was the firstborn child and eldest son of Georg von Trapp and his first wife, Agatha Whitehead von Trapp.  He was a member of the Trapp Family Singers, whose lives were the inspiration for the play and film "The Sound of Music".  He was portrayed as the character "Friedrich".

Martina von Trapp: Martina von Trapp (17 February 1921 – 25 February 1951) was a member of the Trapp Family Singers and was the seventh child of Georg von Trapp and his first wife, Agatha Whitehead von Trapp.  She was a member of the Trapp Family Singers, whose lives were the inspiration for the play and movie "The Sound of Music".  She was portrayed as the character "Gretl".

Supporting paragraphs: Rupert von Trapp Georg von Trapp
Answer: 4 April 1880