IMPLEMENTASI ALGORITMA MATAHARI DALAM EXPLANATORY SUPPLEMENT TO THE ASTRONOMICAL ALMANAC UNTUK PEMBUATAN JADWAL WAKTU SALAT

Abstract

This research is motivated by the many methods of calculating solar data to determine prayer times that are so complex, so that there needs to be an alternative calculation that is simple and easily accessible to anyone. Solar data in the "Explanatory Supplement to the Astronomical Almanac" offers a solution that can answer this problem. This study aims to determine the implementation of the solar algorithm in the Explanatory Supplement To The Astronomical Almanac for making prayer time schedules. This research is a qualitative descriptive study, with primary data sources from the book Explanatory Supplement to the Astronomical Almanac, the book Astronomical Algoritms by Jean Meeus, the book Celestial Mechanics by Rinto Anugraha. For the calculation of the solar algorithm and the data analysis process, in this study the author uses Microsoft Excel software to facilitate the calculation process. The results of the study concluded that there are 9 calculation steps to calculate prayer times with solar data in the "Explanatory Supplement to the Astronomical Almanac" starting from calculating the Julian Day to determining the schedule for entering prayer times. The solar data calculated are the Equation of Time, Solar Declination, and Solar Semidiameter. Then the results of the solar data and prayer times during 1900M - 2100M are fairly accurate, this accuracy is also proven through comparative analysis with the VSOP2000 theory, which shows a low RMSE value for critical aspects such as the Equation of Time, Solar Declination, and Solar Semidiameter. For the RMSE of the prayer time schedule starting from Subuh, sunrise, Duha, Zuhur, Asar, Magrib, and Isha calculated from 1900M - 2100M produces a value of 6 seconds of time