Calculation Using Sightings or Solely Based on Sightings?

Whether calculations or exclusively sightings determine a valid prayer time is a question that falls within the jurisdiction of Islamic scholars and cannot be answered here. What we can answer here are some questions regarding the pros and cons of both opinions.

Let's start with the determination based exclusively on sighting. At first, it sounds very simple, because you only need to find a place where you can observe the horizon. From this place, Fajr, for example, must then be observed and the current prayer time reported. This would then have to be done in this way for every village and every city where Muslims live. However, since this method is subject to strong influence from light pollution, the prayer times deviate significantly from place to place. For instance, a town located next to a brightly lit industrial facility would pray about 30 minutes later than a town 3 km away that does not have as much artificial light on the horizon. The prayer time would also occur temporarily or slightly earlier if there were a power outage. Thus, humans would be able to manipulate the prayer times with their artificial light. Anyone who follows this opinion would, however, have to agree to this. Cases where prayer calendars were created through sightings are not known in Germany to this day. A proper creation of such a calendar would have to be preceded by long-term observations documenting the times weekly and possibly several times a week.

The other opinion is that we calculate the prayer time using values that were determined through observations. Muslims have been able to calculate the prayer time based on the angle of the sun for about 1,000 years. For example, Ibn al-Shatir, the chief Muwaqqit of the Umayyad Mosque in Damascus in the year 777 AH, said: “As for the time of the morning prayer, it is at daybreak, and knowing that, one must place the nadir on the eighteenth arc from the direction of the Maghrib”. Western sources, such as the New American Practical Navigator of 1802, also report on the angle of twilight: “By the preceding method you may find the beginning or end of twilight, by calculating the hour when the sun's zenith distance is 108 degrees (or when the sun is 18 degrees below the horizon); for by observation it has been found that twilight begins or ends when the sun is at that distance from the zenith.” This is long before science categorized the twilight phases. The statements from Islamic astronomers and scholars from history as well as from science are numerous and can be researched by anyone. The fact that Muslims today no longer agree on what the correct angle is can be attributed to several reasons. For one thing, most countries today are too bright to still recognize the initially very faint twilight, which includes the problem that sightings are conducted in places and by people who are not qualified to do so. On the other hand, based on interpretations of some astronomical texts, statements are made without ever having actually conducted a sighting. And there are also people who say that for the angle we only follow the sighting, without taking artificial light into account. With them, the same problems arise that were already mentioned in the previous paragraph. Thus, there can be no degree value that would be valid for all places, and a different degree value would have to be determined by observation for every village and every city, which ultimately means one actually belongs to the other opinion again. According to this opinion, one could no longer say the angle of Fajr is such and such, but only: in our town, the angle is such and such. So if we hold the opinion that we take artificial light into account and use as a basis for the beginning of twilight the first light that becomes visible when no other electrical light is present, we must return to the values of the old astronomers and science. Because there was no one who said that the first light of twilight is present at an angle lower than 18 degrees. Whoever claims this must belong to the other opinion and under certain circumstances may not represent any degree values at all. Thus, it can be said that the correct degree value for Fajr is 18, and Fajr can be seen at approximately this degree value in areas without electrical light. Therefore, Fajr can be calculated for any place in the world using this angle, and that is the opinion of most scholars and astronomers in Islamic history.