What is the ruling on one who fasts in a country and then moves to another country where the fasting differs?
Machine translationRead the Arabic original
The questioner : What is the ruling on one who fasts in a Muslim country and then moves to another country where the people break their fast later than in the first country, and following them requires fasting for more than thirty days, or the reverse?
The Shaykh : If a person moves from one Islamic country to another Islamic country and the breaking of the fast in the country he moved to is delayed, he remains with them until they break their fast, because fasting is the day people fast, breaking the fast is the day people break their fast, and 'Id al-Adha is the day people sacrifice.
And even if this adds a day or more to his fast, it is like if he traveled to a country where the setting of the sun is delayed, in which case it may exceed the usual day by two or three hours or more. And because if he moves to a second country, the crescent moon has not been seen there. The Prophet (peace and blessings be upon him) commanded that we do not fast except upon seeing it, and he likewise said, "Break your fast upon seeing it." As for the reverse, such as moving from a country where the confirmation of the month is delayed to a country where the confirmation of the month is earlier, he breaks his fast with them and makes up what he missed of Ramadan. If he missed one day, he makes up one day, and if he missed two days, he makes up two days.
The questioner : But the listener may ask: Why is he commanded to fast for more than thirty days in the first case, but to make up in the second case?
The Shaykh : Yes, he must make up the fast in the second country, because the month cannot be less than twenty-nine days. It may exceed thirty days because the crescent was not seen. In the first country, we told him to break his fast, even if the thirty days were not completed, because they were approaching. Once the crescent is seen, he must break his fast. Is it possible for you to fast a day of Shawwal? Since you were short of twenty-nine days, you are required to complete twenty-nine days. This is different from the second country, where you are still in Ramadan. If you arrive in a country and the crescent is seen, you are in Ramadan, so how can you break your fast? You are required to remain fasting. If the month extends for you, it is like the extra hours in a day.
The Shaykh : If a person moves from one Islamic country to another Islamic country and the breaking of the fast in the country he moved to is delayed, he remains with them until they break their fast, because fasting is the day people fast, breaking the fast is the day people break their fast, and 'Id al-Adha is the day people sacrifice.
And even if this adds a day or more to his fast, it is like if he traveled to a country where the setting of the sun is delayed, in which case it may exceed the usual day by two or three hours or more. And because if he moves to a second country, the crescent moon has not been seen there. The Prophet (peace and blessings be upon him) commanded that we do not fast except upon seeing it, and he likewise said, "Break your fast upon seeing it." As for the reverse, such as moving from a country where the confirmation of the month is delayed to a country where the confirmation of the month is earlier, he breaks his fast with them and makes up what he missed of Ramadan. If he missed one day, he makes up one day, and if he missed two days, he makes up two days.
The questioner : But the listener may ask: Why is he commanded to fast for more than thirty days in the first case, but to make up in the second case?
The Shaykh : Yes, he must make up the fast in the second country, because the month cannot be less than twenty-nine days. It may exceed thirty days because the crescent was not seen. In the first country, we told him to break his fast, even if the thirty days were not completed, because they were approaching. Once the crescent is seen, he must break his fast. Is it possible for you to fast a day of Shawwal? Since you were short of twenty-nine days, you are required to complete twenty-nine days. This is different from the second country, where you are still in Ramadan. If you arrive in a country and the crescent is seen, you are in Ramadan, so how can you break your fast? You are required to remain fasting. If the month extends for you, it is like the extra hours in a day.
Source
ابن العثيمين - فتاوى الصيام — archive.org (3:54)
The Arabic text is a machine transcription of the audio recording.