The fifteenth of the 1820-21 series of Concerts spirituels conducted by Franz Gebauer included Beethoven’s Eighth Symphony, as well as three choral hymns by Ignaz von Mosel (1772-1844), is held about this time. This performance would conclude the cycle of all of Beethoven’s symphonies in this series (the Ninth having not yet been written). Even though the Concerts spirituels were performed by amateurs, Beethoven must have been pleased at Gebauer’s efforts to keep his music before the public.
The date is conjectural but seems likely; these concerts were almost always performed on Fridays at 4 PM, and except around Christmas and Easter were always about two weeks apart. The last previous definitely-known date in the series was Friday February 23, 1821, six weeks earlier.
Information from Eduard Hanslick, Geschichte des Concertwesens in Wien (Vienna, 1869) at p.190.
The Hanover Band performs the Eighth Symphony here on period instruments: