I’ve been doing a little research to try and understand how the Islamic prayer times are defined. It’s been surprisingly hard to find this information, but I think I’ve basically got it now. Here is what I’ve understood.
The five prayers are, in order, Fajr, Dhuhr, Asr, Maghrib and Isha. Dhuhr (just after noon has passed) and maghrib (just after the sun has set) are straightforward to calculate astronomically – by which I mean, using mathematical equations. Asr is between these two, and seems to be also straightforward, except that its time depends on the school of thought; the two I’ve come across are that it occurs when an object’s shadow is equal to one or two times the object’s length plus the length of its shadow at noon. Fajr and Isha occur before and after sunrise and sunset, respectively, and their starting is determined by the time of appearance or disappearance of refracted sunlight (twilight). These are the two that are not straightforward.
The reason they are not straightforward seems to be that there is no universal algorithm that predicts the appearance or disappearance of twilight based on astronomical conditions such as the depression of the sun beneath the horizon. It seems that the timing of this occurrence varies with geographical location in a non-trivial way. There are methods in place that use a depression angle, and methods that add or subtract a fixed time period after/before sunset/sunrise. These methods are each restricted to particular geographical zones, and have presumably been verified against observations for at least some locations within their respective zones.
As we all know, some latitudes do not ever get really dark during summer, and in some places the sun doesn’t even set. Even where darkness does occur, there can be an extremely short interval between isha and the next fajr. Clearly this poses a juristic challenge, because the early Muslims did not travel to such latitudes and so there is no traditional guidance. This also has implications for fasting during Ramadan, which is performed between fajr and maghrib. Should there be an upper limit to the length of a fasting day, and if so, how should it be defined?
My own feeling, not based on any scholarly opinion, is that when prayer times are too widely or closely spaced, they do not punctuate the day the way I understand they should. If the point of having prayer times is to remember God throughout the day, having enormous intervals between some of the prayers (which is the case during both winter and summer far from the equator) would not seem to achieve this.
I read somewhere that one ruling had suggested that prayer times for latitudes above 45 degrees should be the same as those calculated for a location directly south at 45 degrees latitude – they should follow that timetable all year round, as I understood it. This makes some sense to me because the prayers are then not too widely spaced during summer and not too close during winter. Also, admittedly, it makes the prospect of Ramadan less completely terrifying! Around the time of the longest day, where I am, fajr is around 2:30-3:30am depending on the calculation method, and maghrib after 10pm!
But this rule seems not to be in widespread use judging by prayer timetables I’ve seen. Understandably no-one wants to introduce or endorse a new rule unless they have to; hence, the norm is to calculate the times in the standard way where possible, and the prayers that disappear using this method at high latitude are added in using additional rules, rather than changing all the timings for that location. I can understand it, but I don’t really like it.
Any thoughts? or information? 😛