Analysis Of Mathematical Patterns On Ethnoastronomy For Determining Ramadan And Eid Al-Fitr In Islamic Sasak Tradition Community

Nowadays, determination of Ramadan and Eid al-Fitr using contemporary hisab and rukyat hilal methods. The Ministry of Religious Affairs Republic Indonesia has been using the neoMABIMS criteria of 30 hilal heights and 6.40 elongations. However, there are local communities that still maintain traditional calculation for beginning of hijriya. One of them is Sasak Islamic Community tradition on Lombok. They use certain patterns to determine the entry of Ramadan and Eid al-Fitr. These patterns simply contain mathematical and arithmetic patterns. So it is interesting to study how the mathematical patterns are contained in method of determin beginning of Ramadan and Eid al-Fitr in the Sasak Islamic Community tradition. This research is a field research with a descriptive qualitative approach. While collecting data using observation, interview and documentation techniques. The results of this study showed that the pattern of determin beginning Ramadan and Eid Fitiri by Sasak Islamic Community tradition is a pure of ethnoastronomical patterns in the form of Muharram-puase, Mulud-Lebaran and Bulan Wah Ngelok Jelo. Muharram-puase and Mulud-Lebaran contain basic arithmetic systems that produce simple calculation formulas. Beginning of Ramadan is determined by the day of the 1st of Muharram +5, while Eid al-Fitr is set equal to the day of the maulid of the prophet Muhammad saw in the same year. Meanwhile, the pattern of Bulan Wah Ngelok Jelo is not part of a mathematical pattern because it is not hisab/calculation but observation/traditional rukyah.