Identification of Worst Time on Determining Qibla Direction with Solar Azimuth M. Ihtirozun Ni^am (a), Ahmad Syifaul Anam (a)
a) Universitas Islam Negeri Walisongo Semarang
Jalan Prof. Hamka (Kampus III), Ngaliyan, Kota Semarang 50185, Indonesia
*ihtirozun_n[at]walisongo.ac.id
Abstract
Qibla determination besides requiring fiqh as a basis for its legitimacy, also requires science to implement the concept. So far, the determination of Qibla direction has depended on the Sun as an accurate reference for direction. The daily apparent motion of the Sun makes the Sun^s position in the horizon coordinate system, both its altitude and azimuth values also change. This change will affect the selection of times that should be avoided when determining the Qibla direction. This article aims to identify the worst time to determine Qibla direction. The parameter used is when the azimuth of the Sun changes significantly within 1 minute. This is important to know because the average Qibla determination process can take up to 10 minutes or even more. Meanwhile, at certain times, the change in Qibla azimuth every 1 minute can reach 1 degree. So it is along these times, the Qibla determination can be inaccurate. The method used in this study is exploratory where the author conducted an experiment to calculate the change in the azimuth of the Sun in 1 day on the date the Sun is at the vernal equinox, autumnal euinox, winter solstice and summer solstice at 1 hour intervals, then it is eliminated and recalculated the largest azimuth change within 1 minute intervals. With the calculations performed, it is found that the Sun has a significant azimuth change (> 10 per minute) When the absolute value of: { ( WP + e + BT/15 - TZ) - 12 } x 15 < 150 where WP is Time for determining qibla, e is equation of time, BT is the Longitude, and TZ is Time Zone. In other words, it can be stated that the worst time in determining the Qibla with the azimuth of the Sun is 1 hour before and after the Sun is at its culmination point.
Keywords: Worst Time- Qibla Direction- Solar Azimuth
