He travelled during Ramadaan to a country where the people started Ramadaan on a different day

No File Exists
Check below answers in case you are looking for other related questions:
The fasting person should try hard eat sahoor even if it is a little
What is meant by the black and white threads in the verse on fasting

No File Exists
Related Answers:
Employing non-Muslim workers and allowing them to eat in front of Muslims at the time of fasting
A Christian who fasts in Ramadan
Is it permissible to break the fast before hearing the adhaan?
The fasting person should try hard eat sahoor even if it is a little
What is meant by the black and white threads in the verse on fasting

Recommended answers for you:
Salaat al-tawbah (the prayer of repentance)
Ruling on music, singing and dancing
Ruling concerning women covering their feet in prayer
Muslim bathroom etiquette
Ruling on perfumes containing alcohol