When Sharia texts concerning a particular ruling are general in their indications, any exception needs a specific proof to be excluded from this generality. Applying this rule to those who observe fasting anywhere in the world, they are included in the generality of the texts that prescribe the time between dawn and sunset as the duration of this worship. So, fasting has to extend between these two cosmic signs and no person is allowed to break his or her fast unless the time of sunset actually sets in.

In his response to this issue, Prof. `Ali Jumu`ah Muhammad of Egypt said,

The noble Sharia has made the beginning of the fast and breaking of it conditional on the fasting person’s ability to verify that the day has dawned and that the sun has set, respectively. Almighty Allah says, (and eat and drink until the white thread (light) of dawn appears to you distinct from the black thread (darkness of night), then complete your Sawm (fast) till the nightfall.) (Al-Baqarah 2: 187)
It was also reported in the two sahihs (authentic books of Hadith; i.e., Al-Bukhari and Muslim) on the authority of `Umaribn Al-Khattab (may Allah be pleased with him) that Prophet Muhammad (peace and blessings be upon him) said, If the night approaches from this side, pointing to the East, and the day retreats in this side, pointing to the West, and the sun has set, the one observing the fast should break it“.

All this indicates that what counts in breaking the fast is the fasting person’s ascertaining that darkness has fallen, either physically by witnessing it or through notification by believing a person whose account is considered trustable in this regard. The same applies to imsak (the beginning of the fast), since what counts in determining it is verification on the part of the mukallaf (the person accountable for his or her actions) that the true dawn has set in either physically or through the information provided by a person whose recount is considered trustable in this regard.

Moreover, it is well known that the more a person rises above the earth’s level the more the sunset is deferred (to him or her). This fact is perceived by those who live in high floors, and this is due to the sphericity of the earth.

Hence, the rules of Sharia dictate that the fasting person is not allowed to break the fast except when the sun sets, according to the place where such a fasting person may be. In his book, TabyinAl-Haqa’iqSharhKanz Ad-Daqa’iq, Imam Fakhr ad-Din az-Zayla`i – a Hanafi scholar – said,

It was reported that Abu Musa, the blind jurist and author of Al-Mukhtasar, approached Alexandria and that he was asked about a person who ascends the Alexandria lighthouse and sees the sun a long time after it has set according to the people down in the town, is he allowed to break the fast? He answered: “No, (he is not allowed to break his fast) though the people in the town are allowed to do so, because each person is addressed according to his own conditions”.

Moreover, Ibn `Abideen said in his Hashiyah,

The author of Al-Fayḍ  stated, “And the one who is in a high place, such as the lighthouse of Alexandria, should not break the fast as long as the sun has not set there (as witnessed from above the lighthouse), while the people down in the town are allowed to break the fast if the sun sets according to them before it sets according to him (the person on the lighthouse). The same also applies to the break of dawn, with regard to Fajr Prayer or the sahur (predawn meal before the fast).”

Accordingly, breaking the fast for those who travel by plane is due when they witness the sunset, according to the position where they themselves are. They are not allowed to break the fast according to the timing of the country over which the plane is flying, the country for which they are heading, or the country from which they departed. Rather, they should break the fast upon witnessing the setting of the full disc of the sun. Thus, if – in this way – the duration of their fasting is lengthened in a way that makes fasting difficult for the one capable of observing the fast in the usual cases, then they are allowed to break the fast due to the additional difficulty accompanying the travel and not due to the ending of the daytime, and they are required to make up later for such day/s in which they break the fast.

Consequently, what is claimed by some pilots that the fasting persons aboard are allowed to break the fast according to the timing of the place of takeoff or the place over which the plane is flying is incorrect according to the Sharia

Another case that is worthy of being explained is that in which the sun appears to have set and then resurfaces again in the west because of the high velocity of the plane. In this case, the fasting passengers are allowed to break the fast upon the “first sunset”; they are not required to consider the sun’s resurfacing.