Question: When was the Russian dramatist who wrote The libretto born?

Context paragraphs:
Vladimir Kurochkin: Vladimir Stepanovich Kurochkin (Владимир Степанович Курочкин; 6 February 1829, Saint Petersburg, Russian Empire, - 20 April 1885, Saint Petersburg, Russian Empire) was a Russian dramatist, translator, editor and publisher.  Among the plays he authored were "The Green Island" (as Vlad K-n, with Innokenty Omulevsky; staged in 1873, published in 1883), "Who Is to Blame?"  (1873), "Two by Two is Five" (1875) and "A Modiste's Diary" (1875).  Vladimir Kurochkin compiled and published "Nevsky Sbornik" (the 1867 literary compilation).  He edited "Iskra" magazine (1864–1867) and the Tatar-language "Fayde" (Virtue) newspaper (1866–1870).  Poets Nikolai and Vasily Kurochkins were his brothers.

Iolanta: Iolanta, Op.  69, (Russian: Иоланта ) is a lyric opera in one act by Pyotr Tchaikovsky.  It was the last opera he composed.  The libretto was written by the composer's brother Modest Tchaikovsky, and is based on the Danish play "Kong Renés Datter " ("King René's Daughter") by Henrik Hertz, a romanticised account of the life of Yolande de Bar.  In the original Danish play, the spelling of the princess's name was "Iolanthe", later adopted for the otherwise unrelated Gilbert and Sullivan operetta of that name.  The play was translated by Fyodor Miller and adapted by Vladimir Zotov.  The opera received its premiere on 18 December 1892 in Saint Petersburg.

Vladislav Ozerov: Vladislav Aleksandrovich Ozerov (Russian: Владисла́в Алекса́ндрович О́зеров ) (11 October 1769 – 17 September 1816) was the most popular Russian dramatist in the first decades of the 19th century.

Modest Ilyich Tchaikovsky: Modest Ilyich Tchaikovsky (Russian: Моде́ст Ильи́ч Чайко́вский ; 13 May [O.S. 1 May] 1850 –15 January [O.S. 2 January] 1916 ) was a Russian dramatist, opera librettist and translator.

Pyotr Karatygin: Pyotr Andreyevich Karatygin (Russian: Пётр Андреевич Каратыгин , 11 July 1805, Saint Petersburg, Russian Empire, - 6 October 1879, Saint Petersburg, Russian Empire) was a Russian dramatist and actor.  The tragic Vasily Karatygin (1802-1853) was his brother.

Fyodor Kokoshkin: Fyodor Fyodorovich Kokoshkin Russian: Фёдор Фёдорович Кокошкин ; 1 May 1775, Moscow, Russian Empire, — 21 September 1838, Moscow) was a Russian dramatist and playwright, Moscow government official and theatre entrepreneur, the first director of the Moscow troupe of the Imperial Theatres, in 1823—1831.

Fyodor Koni: Fyodor Alexeyevich Koni (Фёдор Алексеевич Кони, 21 March 1809, Moscow, Russian Empire, - 6 February 1889, Saint Petersburg, Russian Empire) was a Russian dramatist, theatre critic and literary historian, editor and memoirist.  Lawyer, author and politician (1887-1927) was Fyodor Koni's son.

The Seagull: The Seagull (Russian: Чайка , "Chayka " ) is a play by Russian dramatist Anton Chekhov, written in 1895 and first produced in 1896.  "The Seagull" is generally considered to be the first of his four major plays.  It dramatises the romantic and artistic conflicts between four characters: the famous middlebrow story writer Boris Trigorin, the ingenue Nina, the fading actress Irina Arkadina, and her son the symbolist playwright Konstantin Tréplev.

Nikolai Khmelnitsky: Nikolai Ivanovich Khmelnitsky (Николай Иванович Хмельницкий, August 22 [o.s., 11], 1789, Saint Petersburg, Russian Empire, - September 20 [o.s. 8], 1845, Saint Petersburg, Russian Empire) was a Russian dramatist, literary critic and translator.  In 1812-1814, as an army officer, he was Mikhail Kutuzov's adjutant, and later, in 1829-1838, served as a governor of Smolensk.  Khmelnitsky's chosen genre was the saloon comedy, and many prominent authors, Alexander Pushkin among them, valued him as an influential figure of the Russian literary scene of the 1820s.

Nikolai Gogol: Nikolai Vasilievich Gogol ( ; Russian: Никола́й Васи́льевич Го́голь , "Nikolay Vasilievich Gogol"; ] ; 31 March [O.S. 19 March] 1809  – 4 March [O.S. 21 February] 1852 ) was a Russian dramatist of Ukrainian origin.

Supporting paragraphs: Iolanta Modest Ilyich Tchaikovsky
Answer: 13 May [O.S. 1 May]