What is the ruling concerning the fasting the day of 'Arafah?
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, may Allah exalt his mention as well as that of his family and all his companions.
Fasting the day of 'Arafah is a supererogatory act. The Prophet Muhammad has urged people to fast this day. Abu Qataadah, may Allah be pleased with him, narrated that the Prophet Muhammad was asked about observing the fast on the day of 'Arafah, he replied: “'Arafah's fasting removes the sins of two years: the last and the coming year.” [Narrated by Muslim, Abu Dawood, aI-Nasaa'e and Ibn Maajah]
However, fasting the day of 'Arafah is only for those who are not performing Hajj. In regard to those who are performing Hajj, giving up fasting is preferable, so that they can be strong enough to carry out the whole ceremonies of that day such as making Du'aa, staying in 'Arafah, going to Muzdalifah and overnight stay at Muzdalifah and the like. Abu Hurairah, may Allah be pleased with him, that the Prophet has forbidden the fasting of 'Arafah day or in 'Arafah location. (Ahmed and Ibn Maajah)
Moreover, the fasting of the day of 'Arafah is linked to the time and not the place as the day of 'Arafah may differ from one place to another. The pilgrims may stand on the Mount of 'Arafah on Tuesday for instance, but this day may not be 'Arafah day for other countries, rather 'Arafah for them could be on Wednesday because the month in Makkah started before it started in those countries. So if they fasted on Tuesday, they would not really have fasted the day of 'Arafah, rather the Sunnah in their regard in to fast on Wednesday. Therefore, what should be taken into account is the time in each country and not the place which is called 'Arafah, i.e. not the time of the country where the pilgrims stand on the Mount of 'Arafah.
Allah knows best.
Fatwa answered by: The Fatwa Center at Islamweb