There is a concept called Purim Meshulash, the three day Purim that is in Israel. How does that work?
Please send sources.
Purim Meshulash occurs when the fifteenth of Adar falls on Shabbos for walled cities (such as Jerusalem).
In this case, the Megillah is read on Friday (and Matanos La’Evyonim given), Al Hanissim recited on Shabbos, and the Purim feast (and Mishloach Manos) eaten on Sunday. Because Purim runs over three days, the
Shulchan Aruch 688:6 and Mishnah Berurah.