Complex sentence: Daly announced that Schuman's Eighth Symphony would be performed at Philharmonic Hall (now Avery Fisher Hall) the following Thursday, which date, October 4 1962, marked the première of the work.
Split into simpler sentences: Daly announced that Schuman's Eighth Symphony would be performed at Philharmonic Hall (now Avery Fisher Hall) the following Thursday. That date, October 4 1962, marked the première of the work.