Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada states: “In this case the most practical thing to do is to follow the timings of your point of departure until such time that you have arrived at your final destination if you are not stopping over in-between. If, however, you are stopping over at a third point, then while you are there you should follow the local timings and continue to follow the same until you arrive at your final destination.
Let me illustrate this as follows: Suppose you are flying to India or any point in the Middle East such as Saudi Arabia, Kuwait, and so on, via London or Paris, you should follow the timings of Toronto until you have landed in London or Paris. From that point onwards until you have arrived at your destination, follow the timings of London or Paris. What I normally do in this case is pray both Zhuhr and `Asr Prayer at home combined (assuming I am starting at the time of Zhuhr Prayer); then pray both Maghrib and `Isha’ Prayer during the flight as combined and shortened. Then finally I would pray Fajr Prayer during the flight before landing in London. While in London I would pray Zhuhr and `Asr as combined and shortened. I would do the same with Maghrib and `Isha’ Prayers, and so on, until I land.
If, on the other hand, there is no stop over since it is a non-stop flight of seventeen hours, then you should simply follow the timings of your departure location until you have landed at your final destination.
You need not confuse yourself or be overly concerned about some mix-up in timings due to differing time zones. It is a source of great relief for us to know that Islam is a simple and natural religion. We are only required to do what we can in a given situation according to the best means available. The Prophet (peace and blessings be upon him) said, “Remain conscious of Allah, according to the best of your ability.”