Q. This year (5781 - 2021) Purim will be on Friday. Because of the proximity to Shabbat should one start and also end the seudah (feast) of Purim before chatzot (midday)?
A. Rema (O.H. 695: 2) writes that when Purim is on Friday the seuda should be done in the morning due to the honor we are to give to Shabbos. Mishna Berura (10) explains that it means before chatzos. However, it is only lechatchila (preferable).
As far as finishing before chatzos, Horav Shlomo Miller Shlit'a pointed to the Maharil's ruling that it is not required.
Rabbi A. Bartfeld as advised by Horav Shlomo Miller Shlit'a and Horav Aharon Miller Shlit'a