Must a day be made up after Ramadan and Zakat al-Fitr be paid in Saudi Arabia or Pakistan, given that the beginning and end of the month will be in two different countries with a one-day difference?

A Muslim is obligated to adopt the crescent moon sighting of the country he is in, based on the saying of the Prophet, peace and blessings be upon him: "Fasting is the day you fast, and Eid al-Fitr is the day you break your fast, and Eid al-Adha is the day you offer your sacrifice." So, if he enters Saudi Arabia and their sighting of the crescent moon precedes that of his original country, he must adopt their sighting. If they break their fast after 29 days of fasting, he must break his fast with them and make up for the day they preceded him in fasting. As for Zakat (definition) al-Fitr, it should be given in the country where it became obligatory.