Question: Some people come to a city with the intention of residing therein for some years for a specific purpose [e.g., education] During this time, they do not leave their own home-towns for good.

When the specific purpose is accomplished, they leave that city and go to wherever they like. How should they do their salãt and how should they fast [in that city]?

Answer: They shall pray fully; they can fast after having lived in that city for a month just as they do in their own home-towns.
Question: Is it permissible to rely on the European observatories [i.e., non-Muslim experts] for determining the timings of true dawn, sunrise, noon, and sunset for the whole year, including the month of Ramadhãn, knowing well that it is scientific and very precise to the minutes and seconds?
Answer: If one is sure of the correctness of their timings, it is permissible to act upon it. However, one should know that there are some differences in determining the true dawn especially in some of the cities in [northern] Europe [and Canada]; therefore, it is necessary to ascertain that it is based on the proper view.
Question: In some cities, the sun does not rise at all for days or does not set at all for days or even more. How should we pray and fast?
Answer: As for salãt, one should, as a matter of obligatory precaution, observe the closest place that has night and day in a twenty-four hour period, then say salãt according to its timings with the intention of mutlaqa [i.e., just qurbatan ilal lah without specifying whether it is ada (on time) or qadhã (after time)]. As for fasting, it is obligatory upon you to move during the month of Ramadhãn to another city where you can observe fasting of this holy month, or move to that city after that month to perform it qadhã.
Question: Can a person who is fasting in the holy month of Ramadhãn serve food to non-Muslims?Answer: By looking at the issue on its own merit, there is no problem in it. Question: Would use of a nozzle spray that facilitates breathing invalidate the fast?
Answer: If the spray that comes out of the nozzle enters the respiratory tract and not the passage of food and drink, it does not invalidate fast.Question: Does the nutrition given, intravenously invalidate fast irrespective of whether or not it was absolutely necessary for the patient?
Answer: In both the cases, it does not invalidate the fasting. Question: Does masturbating during daytime of Ramadhãn invalidate the fast, regardless of whether or not it leads to ejaculation? What is the penalty that should be incurred by one who does so? What is the ruling for a woman who engages in masturbation during daytime of Ramadhãn, irrespective of whether or not it leads to discharge?
Answer: If a person masturbates with the intention of ejaculating and actually ejaculates, his fast is rendered invalid and he must make it up by way of qadhã as well as pay the penalty (kaffãra) which is fasting for two successive months or feeding sixty poor people. If he masturbates with the intention of ejaculating but does not ejaculate, he must complete the fast with the intention of pleasing the Almighty and then do it qadhã.If he masturbates without the intention of ejaculating and he does not normally ejaculate, knowing that discharge is probable and it actually happens —he has to do qadhã without the penalty.
However, if such a person was confident that no discharge would take place and it actually happens — no qadhã is required. In all these cases, there is no difference between a man and a woman.
Question: A believer fasts but does not know that intentionally getting into state of janãbat invalidates fasting—what should he do [when he finds out]?Answer: It is obligatory on him to make up those fasts; however, there is no penalty on him as long as he was [erroneously] convinced that being in a state of janãbat does not invalidate fast or was unaware of that ruling.
Question: According to some jurists, a person who intentionally invalidates his fast during the month of Ramadhãn by committing a sin has to pay all three kinds of penalty [that is, fasting for sixty days, feeding sixty poor people, and emancipating a slave].
What should a person therefor do during our time when emancipating a slave is impossible since there are virtuallyno slaves?Answer: The penalty of emancipating a slave is waived when it is no more possible. It should, however, be clarified that in our view, it is not obligatory to pay all three kinds of penalty for invalidating a fast during Ramadhãn by committing a sin. And Allãh knows the best.
Question: If the new moon is sighted in the East, does it apply to us also in the West? And if it is sighted in America, does it apply to Europe also?
Answer: If the new moon is sighted in the East, it also applies to the West as long as the latitude of the two locations are not greatly further away from one another. If the new moon is sighted in the West, it does not apply to the East unless it is proven—even by the moon staying on the first [Western] horizon for the length of time that is longer than the difference between the sunset of the two locations. [For example, if the sunset in the Eastern city was half an hour before the Western city where the moon was sighted, and the moon stays on the horizon longer than half an hour —the Eastern city can follow the moon sighted in the Western city.]
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In Minhãju ’s-Sãliheen, it says: “The new moon is proven through the knowledge acquired by sighting or recurring reports etc., and through credible reports of its sighting, etc.” In ruling No. 1044, it says: “If the new moon is sighted in a city, it is sufficient for other cities, provided they share the same horizon, in the sense that the actual sighting in the first city would necessarily be followed with the sighting in the second city if there were no barriers like clouds, fog, mountains, etc.”
In the light of what has been quoted, the following questions arise:
Question: Would the sighting of the new moon in cities in the East like Iran, Ahsã’, Qatíf [both in Arabia], other countries in the Gulf, Iraq, Syria, and Lebanon necessarily be followed by its sighting in Western countries like England, France and Germany if there were no barriers like clouds and fog?Answer: Yes, the sighting of the new moon in an area would necessarily be followed —provided there were no barriers— in places which are located to its west as long as they are not far apart on the latitude lines.
Question: If the answer to the previous question is positive, would the occurrence of the sighting of the new moon in the view of some religious scholars in Eastern countries be a sufficient evidence for one who is residing in Western countries even though the sighting of the new moon did not occur in those places for lack of clear skies?
Answer: It will not be a sufficient evidence for him or for others. However, if the occurrence of the sighting from the view point of those religious scholars attracts trustworthiness in that person that the moon was actually sighted or proof was established about the sighting without any counter proof —even in the form of a ruling— that person can act on what he believes is true.
Question: During certain months, it is declared that the sighting has been proven according to some religious scholars in some Eastern countries. This is based on the testemony of those who have sighted the new moon. Such declarations are usually coupled with the following facts: The witnesses who sighted the moon and who number around thirty, for example, are scattered in various cities such as 2 in Isfahan, 3 in Qum, 2 in Yazd, 4 in Kuwait, 5 in Bahrain, 2 in Ahsã’, and 6 in Syria, etc. The sky was clear in a number of cities in the West, and the believers went out in the attempt to sight the moon; and there was nothing preventing the sighting.
The observatories in England announced that it was impossible to sight the new moon that evening in England except by using a telescope; and that its sighting with the naked eye would be possible only in the following night. So, what is the ruling in such a case? Please guide us, may Allãh reward you.
Answer: The criterion is the satisfaction of the individual himself  about the actual sighting [of the new moon] or  the proof of sighting without any counter claim.In the case mentioned above, satisfaction is not normally achieved concerning the appearance of the new moon on the horizon in such a way that it could have been sighted by the naked eye. On the contrary, one is satisfied that it was not sighted and that the testimony [of sightings in the Eastern cities] is based on illusion and error in sight. And Allãh knows the best.

Source: en.shafaqna.com