The rationale for the salat timesheet

Introduction

Life in the cities and the many occupations have led Muslim communities to make use of sheets and schedules that mark the time of the salawat. In them, two fields that were familiar since post-classical antiquity have coincided, with greater or lesser success: fiqh and astronomy. As is well known, the belief fostered scientific knowledge – particularly mathematics and astronomy – in a healthy relationship that is difficult to recognize today.

Fiqh and its interpretation

In fiqh – we focus here on the malaiki – the entry of the moments of salat is well defined:

-) Fayar: moment when the first sign of luminosity begins to be perceptible in the environment due to the dawn, and ends shortly before dawn.

-) Duhur: moment immediately after the one indicated by having the objects vertically placed their minimum shadow in the day.

-) Roasting: the moment when the shadow of vertically placed objects measures the same as the minimum shadow plus the length of the object.

-) Maghrib: the moment when the solar corona is hidden by the horizon, although the luminous effects of its rays on the environment persist.

-) Isha: moment in which all vestiges of the sunlight of twilight disappear.

Mathematical interpretation

The main problem in mathematically interpreting fiqh arises from conceiving the concept of twilight, light scattered by refraction in the atmosphere before sunrise (sunrise) and after sunset (dusk). Twilight has been associated with solar depressions of 6 (civil), 12 (nautical) and 18 (astronomical) degrees. The moment of the fajar (respectively isha) is indicated by reaching astronomical twilight and decreasing (respectively increasing), although different solvent groups of Muslims have adopted other criteria for the angle varying the choices between 15 and 19.5 degrees, even distinguishing in the use of the angle according to whether it is the isha or the fajar. In Grenada, for example, the angle of 18 degrees is used for both moments, as in the Karachi University of Islamic Sciences. The ISNA (Islamic Society of North America) sets it at 15, indifferently.

The calculation of the sunset and its rise is very delicate, as many factors that are difficult to weigh influence: shape of the horizon, nature of the coordinates that are considered (topocentric versus geocentric), influence of the refraction of light (depends on the density of the atmosphere), height of the place, extension of the area of validity of the calculations, orography of the area, etc. In most cases, topocentric coordinates are taken for the calculation, the refraction of light for an apparent sunset is included and the height of the highest place in the validity area is taken into consideration.

The calculation of the times of duhur and roasting has no difficulty and is free of controversy, regardless of the guideline of the school followed.

Using the Time Table

When there is a time table with the characteristics explained above, as is the case of the city of Granada (Spain), it must be used carefully. The main guidelines explained by moments of salat are the following:

-) Fayar. It has been observed that calculated with astronomical twilight a lot of fidelity is obtained. Without going any further, moments later the bustle of the birds is born as they begin their daily activity. From that moment on, one can pray and one can stop eating some time before it in Ramadan. We believe that angle is ideal. The fajar prayer should not be postponed to the calculated moment of sunrise, since the sun will have risen, although the visibility of the corona will depend on the irregularities of the horizon.

-) Duhur. Most theorists and calculation recipes put the entry of this time at five minutes of the astronomical noon of the place. It is a long time of prayer.

-) Roast. The prayer can be made at the time fixed by the calculation.

-) Maghrib. In the cases referred to above for the calculation of the Maghrib, the Maghribprayer can be offered just at the calculated time and also break the fast. In any case, on the matter of the sunset we never believe that we are pessimistic enough, given the enormous complexity of calculation referred to above.

-) Isha. We are inclined to consider that the moment of the isha and the fayar are symmetrical and that they should be calculated by the same angle of 18 degrees. However, from experience, we do not consider the asymmetry in the calculation to be unreasonable: to consider for the fayar the angle of 18 degrees and for the isha the angle of 17. This means that the isha would be somewhat ahead of herself. In any case, the prayer of this moment can be made immediately when the time fixed by the calculation arrives.

General considerations

Any schedule for prayer is mere advice, which would be subject to the observation of the worshiper. However, a well-made table should not be underestimated given its unifying value.

The one who uses a table should make preliminary inquiries about different aspects of its preparation. A table that does not take into account the refraction of light as a calculation factor for the Maghrib should be discarded, especially if it does not take into account the height of the site. This last trait would be enough to rule it out. It makes no sense to use a valid sheet in an area of a few square meters; Should each neighbor have his own? The use of the blade should be detached from the attitude of compulsion, especially in Ramadan. Especially in this month, what is accepted without it throughout the year should never serve as a controversy.

Yahya Garcia.

Yahya García holds a PhD in Science from the University of Granada, specialising in logic, is a professor of mathematics for computer science, programmer and translator from Arabic to Spanish. Amateur astronomy and observation.