The birthdate of Gotthold Eisenstein is Apr. 16, 1823 as is stated in the Wikipedia. But a letter(whose recipient is Gauss) of Encke on Oct. 11, 1852 clearly states that the birthdate of Eisenstein is Apr. 10(see the last page of the quoted letter). The date is also implied by the calculation of Gauss on the same page of the letter.
Question: What is the exact birthdate of Eisenstein?