Q. Can one eat meatchicken Motzei Tishah B’av this year since the fast is a nidche?
A. Remah (Shulchan Aruch O.H. 558: 1) rules that meat is not permitted on the night after Tisha Beav, even when it was nidche (transferred) to Sunday, as in this year. It is permitted from the morning (Monday).
I quote a relevant question (1808).
Q. On the night after the end of Tisha Beav (on Sunday, when Tisha Beav falls on Shabbos) I know we can not eat meat yet until the morning, but can you already listen to music?
A. Shoshanas Yisroel (Ben Hametzorim 15: 12: n. 331) maintains that you are not allowed to play or listen to music until the morning, since this is regarded more severe than eating meat.
Horav Shlomo Miller’s Shlit’a opinion is that you are allowed.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a.