Dear Rabbi, I live in Jerusalem and will be in the north of Israel for Purim and will read the Megilla there with my son and join his family for the Purim Feast. I intend to spend Shusan Purim at home in Jerusalem. Do I have to arrive in Jerusalem in time to read the Megilla in the evening as I will be davening Shaharit, where the Megilla will be read, in the morning? Thank you and Purim Sameah,

Since your planned intention is to be in Jerusalem on the 15th of Adar and you will be there physically before daybreak, then you will have the full obligations of Shushan Purim as well, which will require you also to hear the megilla on the eve of Shushan Purim. (See Shulchan Aruch 688 and mishna brura there 12. Rav Tzvi Pesach Frank zt"l in Kerem Tzion Vol.10, Mikraei kodesh on the laws of Purim of Rav Moshe Harari Shlit"a pgs. 101-103.) Have a happy Purim It has been some years since I wrote my original answer and it is only appropriate to add a few more details. Indeed according to Rav Tzvi Pesach Frank zt"l in Kerem Tzion Vol.10 which then later appeared in Shut Har Tzvi Orach Chaim Vol II: 118,(and Orach Chaim Vol II: 128:15) a person who lives in Yerushalayim but has already heard Megilla on the 14th of Adar outside of Jerusalem (in any non- walled city from the time of Yehoshua Bin Nun ) is required to hear Megilla again with the berachot upon his return to Yerushalayim on the eve of the 15th of Adar, or if this person on the 15th of Adar moved and became a resident of Yerushalayim. (see also Biur Halach 688:5) According to former Chief Rabbi, Rabbi Avraham Shapira zt"l ( ימי פורים pg. 34) in the above case when a resident of Yerushalayim returns to Yerushalayim after having heard the Megilla outside Yerushalayim, must hear the Megilla again according to most Rishonim. If a resident from any non- walled city from the time of Yehoshua Bin Nun, heard the Megilla on the 14th and then decides to spend the 15th in Yerushalayim, according to the Ran, Riaz and Ritva, he must hear the Megilla but not according to the Meiri. However, there are those who are of the opinion, that once a person has fulfilled his Purim obligations, he does not do Purim over again. ( Piskei Teshuvot 688: note 71.) However, even according to the opinion that when a resident of Yerushalayim returns home on the eve of the 15th after having heard the Megilla on the 14th, there are many who make the reservation that it is preferable that this person does not say the Berachot for others who haven't heard Megilla at all. . ( Piskei Teshuvot 688: note 71, Mikraei Kodesh, Purim of Rav Moshe Harari Shlit"a pg. 103 in the third edition 5763.) Happy Purim once again and Besorot tovot