All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
When the Muslim moves from one country to another during Ramadan, he should act according to the country to which he moved. He fasts with them, breaks the fast with them and celebrates Eed with them. He should never fast ‘Eed day. If, at the end, he finds that he has fasted less than 29 days then, he has to fast the difference as the month cannot be less than 29 days.
Allah knows best.