Perpetual Prayer Timetables are also known as Timetables for All Time or Prayer Timetables that can be used forever. It is designed to provide a guide to the beginning of prayer times that can be used indefinitely. This name reflects its permanent nature for determining prayer times [10]. The schedule contains prayer times that are valid for a whole year, from January to December. The Perpetual Prayer Time Schedule format usually interpolates dates between 3 to 5 days, so that the schedule can be presented in a compact format on a single datasheet. This aims to facilitate the presentation and understanding of the schedule [11].

In the community, this timetable is widely circulated and can be easily found in many mosques, both in the city center and in rural areas. These timetables have also been found on Ferries crossing between islands, such as between Merak and Bakauheni. Some examples of prayer timetables that are widely circulated in the community include [12]: Prayer Time Schedules for Tanjung Karang, Teluk Betung, Panjang, Metro, and Menggala Areas were calculated by Arius Syaikhi, who also calculated similar schedules for areas in Kalimantan and Sumatra, specifically West Sumatra. Perpetual Prayer Time Schedule published by the Indonesian Mosque Council (DMI) of Batang Regency for Pranten Village, Bawang Subdistrict, Batang Regency. KH Noor Ahmad SS Prayer Time Schedule for various cities such as Jogjakarta, Jepara, and Surabaya. All-time Prayer Time Schedule Pontianak West Kalimantan by H. Abdurrani Mahmud. Prayer schedule of the Holy Tower Calendar by KH Turaichan Adjhuri. Timetable of Prayer Times for Lombok Island by TGH. Ibrahim Al-Khalidy

Some of these prayer timetables include the name of the hasib who did the calculations and others only list the institution that reproduced and circulated them. Examples of timetables that do not include the hasib include the prayer timetables for the Jakarta area found on the Jemla Ferry and Menggala Ferry on the Merak-Bakauheni crossing, as well as the prayer timetables for the city of Bandung and its surroundings circulated by Dahlan's bookshop or book [13]. Furthermore, all-time prayer timetables circulating in Indonesia can be categorized into the following types [14]:

A schedule that applies to one specific city.

Schedules that use the conversion system (Regional Time Correction) from neighboring regions, between cities, and between countries.

Schedule with locations that have latitude differences between 1˚ and 5˚.

Of these categories, especially the schedules that use the conversion system (Regional Time Correction) with the surrounding area, between cities, and countries, have a significant influence in determining prayer times. Prayer schedules that use conversion or time correction with the surrounding area produce two types of data, namely: First, fixed data and Second, variable data [15] . The conversion system between cities that have a latitude difference of no more than 1˚ produces fairly consistent data such as the correction of prayer times between Semarang and Pemalang. These two regions can use the conversion system because the data is consistent. However, data that is not constant or variable, such as the correction of prayer times between Bukit Tinggi and Padang Sidempuan, and between Pontianak and Kendawangan, cannot be used as a reference in converting prayer times [16] .

Furthermore, schedules that use inter-city and cross-country conversions produce inaccurate time correction data throughout the year. Therefore, prayer timetables that utilize city-to-city and cross-country conversions cannot be used as an accurate reference in determining prayer times [17]. Latitude differences between locations of 1˚ (1 degree) or more using the conversion system in the preparation of timetables can significantly affect the determination of prayer times. If the latitude difference between two locations reaches 1 degree or more, then the Zuhr time will not be significantly affected, because the difference results in a time difference of 0 minutes. Thus, the Zuhr time can use a prayer timetable based on the conversion system. However, for the other four prayer times, Fajr, Asr, Maghrib, and Isha result in varying prayer times [18].

The maximum latitude difference for the Asr and Maghrib times is 1˚ 20', while for the Isha and Fajr times it is 1˚. Therefore, prayer schedules that use the conversion system between regions, cities, and countries with latitude differences exceeding the maximum limit, can affect someone praying not on time and also affect the fasting of Muslims [19].

TGH. Ibrahim Al-Khalidy al-Anfanani was born in Muharram 1330 H/1912 M. His father was named TGH. Khalidi. TGH. Khalidy is a master teacher who was born from the noble lineage of the Selaparang kingdom of Lombok. TGH. Ibrahim Al-Khalidy's childhood was spent in Lombok learning the Koran with his father until the age of eight. The atmosphere of a religious family makes the figure of little Ibrahim grow up in a family that daily provides religious enlightenment for young people in Kediri Village, which is now known as the city of santri in West Lombok. At the age of 10, Ibrahim was sent and entrusted by his parents with TGH. Muhammad Arsyad Sumbawa followed his brothers, Abdussatar al-Khalidi and Mustafa alKhalidy who were studying in Makkah al-Mukarramah in 1918 AD at the end of World War 1.

In the Risalah Siraj al-Qulub fi 'Ad'iyah 'Allam Al-Ghuyub written by TGH. Ibrahim in 1974 in Makkah al-Mukarramah, the names of the masters from Lombok, the archipelago and the ulama'-ulama' of Haramayn who were his teachers while studying there are listed Some of them were Nusantara ulama'-ulama' who settled in Makkah and most of them were Hijaz ulama'-ulama' in the early 20th century. Ulama'-ulama' Haramayn originating from the archipelago who became his teacher include: KH Marzuki Palembang, KH Hasan Jambi, Sayed Sheikh Muhammad Nur Fathani, KH Salim Cianjur, KH Raden Ahyad Bogor, KH Abdul Qadir Mandahiling, KH Husain Palembang, KH Abdurrahman Klantan and KH Ahmad Payakumbuh.

His teachers from the scholars of the Hijaz include: Sheikh Abbas Abdul Jabbar, Sheikh Hasan Yamani, Sheikh Isa Ruaes, Sheikh Abdullah Al-Khadrami, Sayed Abbas Maliki, Sheikh Umar Hamdan, Sheikh Jamal Maliki, Sheikh Sayed Alwi Ibn Abbas al-Maliki, Sheikh al-Hadrami, Sheikh Ali Maliki, Sheikh Khalifah Ibn Nabhan (his teacher in Falak science), Sheikh Sayed Muhammad Amin Kutbi, Sheikh Ibrahim al-Tikrani, Sheikh Muhammad Nur Saiful Bahrain, and Sheikh Hasan Masyath. From the notes written in the book Siraj al-Qulub fi 'Ad'iyah 'Allam Al-Ghuyub by TGH. Ibrahim Al-Khalidy one of his teachers in Falak Science was Sheikh Khalifah Ibn Nabhan (1270-1366 H). Sheikh Khalifah Ibn Nabhan was known as a scholar who was very pious and used as a reference, an expert in jurisprudence, mathematics, and astrology. He died at the age of 96.

Sheikh Khalifah wrote many books, including a book on Falak entitled [20]:

Al-Wasilah al-Mar‟iyyah li Ma‟rifah al-Awqat asy-Syar‟iyyah.

Tsamarat al-Wasilah li man Arada al-Fadhilah, this book is a summary of the book al-Wasilah al-Mar'iyyah. Published in 1328 AH at the expense of the alHashimiyyah government, it was published many times. This book is used as a curriculum for Tsanawiyah (Aliyah) in Darul Ulum Diniyyah Madrasah Shaulatiyah and a number of Madrasahs in Indonesia and Malaysia.

Kitab Jadwal ad-Da-iroh al-Maghni-thisiyyah li Ma‟rifah al-Qiblah al- Islamiyyah, This book is summarized from Risalah al-Mu‟allim asy-Syadzili.

Risalah Rasm al-Basa-ith, Summarized from Risalah Abdul Ghani Mahmud.

Risalah fi al-Awqat wa al-Qiblah bi al-Jadawil as-Sittiniyyah

At-Taqrirat an-Nafisah fi Bayan al-Basithah wa al-Kabisah, This book contains the initial table of constellations in the Arabic calendar up to '1600 H.

Manzhumah fi Manazil al-Qamar.

The maximum latitude difference for the Asr and Maghrib times is 1˚ 20', while for the Isha and Fajr times it is 1˚. Therefore, prayer schedules that use the conversion system TGH Ibrahim Al-Khalidy stayed in Makkah for approximately 20 years to study, after returning from Makkah, he practiced his knowledge in Lombok. TGH Ibrahim Al-Khalidy together with his brother TGH Mustafa Khalidy established Al-Ishlahuddiny Kediri Islamic Boarding School in West Lombok as the first step in developing Islam on Lombok Island. TGH Ibrahim al-Khalidy is also known as a diligent writer. His works and thoughts include:

Matn Tuhfah al-Shibyan fi 'Aqa'I al-Imam, written in Arabic then arranged in the form of Nazhom (sha'ir), consists of 42 stanzas, written in 1361 AH using bahr Rajaz. This book discusses the science of Tawheed and a glimpse of the lineage of the Prophet Muhammad in the form of a Nadzam.

Risalah Siraj al-Qulub fi 'Ad'iyati 'Allam al-Ghuyub, This treatise is a collection of wirid and dhikr received from the scholars of Haramayn.

This treatise was issued as the 19th material for the recitation of the Abituren of the Al-Ishlahuddiny Islamic Boarding School. This treatise contains the opinions of four madhhab imams about the arrival of the reward of reciting the Quran, tahlil, Tasbih, and other practices for deceased Muslims.

Brochure of Abiuren Studies.

TGH Ibrahim al-Khalidy is not only known as a fiqh expert but also as a phalaxist. He learnt astrology from Kiyai Jawi who came from Bogor and taught at the Grand Mosque. The book he studied was Taqribul Maqshad fi amali bi Rubbi al-Mujayyab written by Sheikh Muhammad Mukhtar bin 'Atharid al-Bughuri [21] . He studied Falak Science not through formal education, but by using the halaqah method. Although he only used the halaqah method, his knowledge in the field of falac science cannot be doubted. After completing his study of falak science at the Grand Mosque, he then opened a falak recitation every Ramadan at the Mecca Al-Ishlahuddiny Mosque. In the recitation, he taught the book Taqribul Maqshad fi amali bi Rubbi al-Mujayyab for one month during the day until he finished the book [22] .

One of his works in the field of astrology is the Timetable of Prayer Times for the whole island of Lombok. This prayer schedule was compiled in 1993 at the initiative of TGH. Ibrahim al-Khalidy's students. In the preparation process, TGH. Ibrahim al-Khalidy acted as a proofreader. Some of the students involved in formulating this prayer schedule include TGH. Agussalim Idris, the late Ustadz. Rahmatullah, TGH. Busyairi, and other students. The schedule of prayer times of times is prepared based on the calculations contained in the book Taqribul Maqshad fi amali bi Rubbi al-Mujayyab. The calculation tool used is Rubu' Mujayyab [23]. This prayer schedule is the result of collaboration between TGH. Ibrahim al-Khalidy and his students in making calculations.

TGH. Ibrahim Al-Khalidy's Perpetual Prayer Times Calculation Markaz takes the West Lombok Region and the calculation format used in the Schedule covers the entire island of Lombok without distinguishing between East Lombok, Central Lombok, West Lombok, or North Lombok. Therefore, no regional time correction is applied in this prayer schedule for other locations on Lombok Island. According to TGH Ibrahim al-Khalidy, the omission of this regional time correction is because the distance between Ampenan and North Lombok is still within one marhalah. One marhalah is estimated to be around 82 kilometers, and this distance is the minimum limit for someone to be allowed to make up their prayers. Therefore, there is no difference between the prayer times for East Lombok, West Lombok, Central Lombok, or North Lombok. So, this schedule can be used for the island of Lombok. As for areas outside the island of Lombok, regional time corrections are made. The regional time correction for other than the Lombok region which is included in the NTB region is in the table below:

The Timetable of Prayer for All Time is then disseminated through the IKABA recitation organized by TGH. Ibrahim al-Khalidy. This IKABA recitation involves all congregations, majlis ta'lim, sympathizers, and extended families of alumni who have studied or studied formally or informally in institutions and under the auspices of Ponpes Al-Ishlahuddiny, wherever they are. Until now, the schedule is still being disseminated through monthly recitations at the Mecca Mosque.

TGH. Ibrahim al-Khalidy in the preparation of the schedule of prayer times throughout the special period of Lombok Island NTB uses a reference source from the book Taqribul Maqshad li amalil birrubu' mujayyab by Sheikh Muhammad Mukhtar bin 'Atharid alBughuri. The book consists of an introduction (muqaddimah), there are 14 chapters, and a conclusion. The calculation tool used in compiling the prayer schedule during the period of TGH. Ibrahim al-Khalidy is Rubu Mujayyab. The method of using Rubu' Mujayyab as a prayer time calculation tool is based on the book Taqribul Maqshad li amalil birrubu' mujayyab [24] .

Rubu' or Quadrant in English has been used as a tool for calculating and observing celestial objects since around the 2nd century AD by Ptolomeus and other Greek astronomers. Ptolomeus' quadrant was made of wooden or stone planks, in the shape of a quarter circle divided into 90 degrees. Furthermore, the center of the quadrant provided a drawing that gave the distance of the Sun calculated from the zenith on the meridian line [25] . Later, the rubu instrument during the golden age of Islam underwent development in the curve at its center. The rubu' was developed by Muhammad Ibn Musa Al-Khwarizmi, a 9th-century Islamic scientist in Baghdad. Rubu' was used for astronomical observations and calculations, such as calculating trigonometric values [26] .

In addition to the calculation tool using Rubu' Mujayyab, the coordinate data was used in the calculation of the prayer schedule throughout TGH. Ibrahim al Khalidy is sourced from the translation of the book Taqribul Mashad, namely [27]:

The prayer time calculation algorithm is used in the preparation of the prayer schedule during the lifetime of TGH. Ibrahim al-Khalidy is as follows:

Analysis of the Calculation of the Timetable of Prayer Throughout the Time of Lombok Island by TGH. Ibrahim

Hisab methods for the beginning of prayer time are divided into two categories: classical methods and contemporary methods. Classical Method Uses calculations that do not update data on the movement of the sun for Position J2000, with an accuracy of up to minutes. Example: Kitab Durus al-Falakiyah by Sheikh Ma'shum bin Ali and Kitab Syawariq al-Anwar by Kyai Noor Ahmad SS. Whereas the Contemporary Method uses algorithms with more detailed data and accuracy up to units of seconds, updated in real-time based on the movement of celestial bodies. Examples of algorithms: Ephemeris Hisab Rukyat system by the Ministry of Religious Affairs and Jean Meeus algorithm. There are also software such as WinHisab and Accurate Times by Muhammad Odeh [36].

The calculation model used by TGH. Ibrahim Al-Khalidy refers to the following:

The data and calculation algorithm contained in the book Taqribul Maqshad fi amali bi Rubbi al-Mujayyab can be categorized as hisab taqribi (approach) [37]. This is due to the use of relatively old data and an algorithm that calculates the position of the Sun based on the average movement of the zodiac. The algorithm also assumes the Sun's declination value is fixed, which has implications for the accuracy of the prayer schedule calculation. Thus, the level of accuracy in the calculation of this prayer schedule tends to be less accurate. In addition, the calculation tool used is Rubu Mujayyab. The accuracy of the Rubu Mujayyab is highly dependent on its physical size. The larger the size of this tool, the higher the level of accuracy. Conversely, when the size of the Rubu Mujayyab gets smaller, the level of precision will also decrease. This shows that the size of the tool plays an important role in the accuracy of the resulting prayer time calculation results [38].

The calculation model applied by TGH Ibrahim Al-Khalidy in preparing the prayer schedule uses an approach that calculates prayer times based on one geographical coordinate which is then generalized for the entire island of Lombok. This method is used by TGH Ibrahim Al-Khalidy because according to TGH Ibrahim Al-Khalidy for one island of Lombok, no regional time correction is needed. After all, it is still within 1 marhalah (82 Km) calculated from Ampenan to East Lombok. So that it equalizes all times for all places in the Lombok area.

The consequences of this calculation model are several important aspects as follows:

Coordinate Generalisation: TGH. Ibrahim Al-Khalidy uses one coordinate as a reference for the entire island of Lombok. This approach aims to simplify the calculation of prayer times but also results in ignoring the different latitude values in each region.

Influence on the Sun's Declination: By ignoring latitude differences, the determination of the Sun's declination becomes less accurate. The Sun's declination is the angle between the Sun's rays and the plane of the equator, which varies depending on geographical position. This neglect can affect the prescribed prayer times.

Implications of the Sun's Position: As a result of this approach, the position of the Sun is considered the same throughout Lombok, although there are differences in latitude values that can affect prayer times. This causes inaccuracies in the compiled prayer schedule.

Time Correction: This does not consider refraction, altitude, and semi-diameter of the Sun, which can affect the accuracy of prayer times.

The calculation of prayer times with refraction correction, altitude, and semi-diameter of the Sun is required for the calculation of prayer times Maghrib, Isha', and Fajr. Especially for the determination of maghrib prayer time, the altitude of this place is very influential. The altitude of this place affects the horizon line seen. Places that have a high altitude will be slower to see the Sun set while places that are lowlands will see the Sun set faster than highlands. Of course, this phenomenon will affect the beginning of Maghrib time. Lowlands will enter the beginning of maghrib time earlier than the highlands.

The location of the island of Lombok in the middle is Mount Rinjani, resulting in many villages that are on a fairly high plateau. So it requires correction of the altitude of the place to find out the ufuk mari. There is a significant difference between the prayer times calculated using 0 meters altitude and 700 meters above sea level data, especially for maghrib time. Moedji Raharto said that the time difference between the two reference differences is about 4 minutes. The schedule that calculates concerning 0 meters will be 4 minutes faster than the comparison. This difference cannot be underestimated because it is classified as a large difference, especially if it occurs during the month of Ramadan [39] .

Regional Time Correction: This generalization also ignores regional time corrections, which are essential for determining the Sunrise and Sunset times. Without this correction, the set prayer times do not match the actual times in each region. The largest difference between Mataram and East Lombok is about 1 minute 44 seconds. This difference is small but will impact the prayer time for East Lombok by 1 minute 44 seconds faster than the prayer time in Mataram.

Lack of Time Conversion: The prayer times schedule was created by TGH. Ibrahim Al-Khalidy does not include time conversions for specific regions, such as Central Lombok, East Lombok, or North Lombok. This means that time differences that may exist between these areas are not taken into account, which may result in incompatibilities in the performance of prayers in various locations.

Accuracy of TGH. Ibrahim Al-Khalidy's Perpetual Prayer Time Schedule and Spiritual Contributions to the Achievement of the SDGs

In testing the accuracy of the prayer schedule during the time of TGH. Ibrahim al-Khalidy, the author applies the calculations formulated by Slamet Hambali in his book entitled Falak Science 1, published by the Postgraduate Programme of IAIN Walisongo Semarang as a reference. Furthermore, to compare the results of the calculation, the author uses the coordinates used by the Ministry of Religious Affairs of NTB in preparing the Imsakiayah schedule for Ramadan 1441 AH.

The author tested the accuracy by calculating the prayer times in Mataram, West Lombok, Central Lombok, and East Lombok on 1 June, 22 June, and 22 December from 2016 to 2020. Thus, each region will have its prayer times calculated for five years on the specified dates. The purpose of this test is to determine the difference in prayer times each year as well as the difference in prayer times between different regions within the five years. The selection of 1 June, 22 June, and 22 December is based on the reason that 22 June is when the Sun is at its northernmost position from the equator, known as maximum positive declination. Meanwhile, 22 December is the turning point of 22 June, where the Sun is at its southernmost position from the equator or maximum negative declination. Meanwhile, the date 1 June was chosen randomly.

Table 3. Comparison of the Calculation Results of 1 June, 22 June, and 22 December 2020 Contemporary Calculation System with TGH. Ibrahim Al-Khalidy Perpetual Prayer Time Schedule on Lombok Island. For complete results from 2016, 2017, 2018, 2019, and 2020 can be seen in the attachment of this link. Based on the calculation accuracy test carried out 300 times starting from 2016 to 2020 with the coordinates of Mataram, West Lombok, East Lombok, Central Lombok, and West Lombok, there are some differences in the results of the calculation of the beginning of prayer time as shown in the table below:

Table 4. Recapitulation and Percentage of Difference between TGH. Ibrahim Al-Khalidy's Perpetual Prayer Time Schedule on Lombok Island and the Contemporary Hisab Calculation System on 1 June, 22 June, and 22 December within 5 years (starting in 2016, 2017, 2018, 2019, and 2020) Juni, 22 Juni dan 22 December within 5 Years (start Year 2016,2017,2018,2019, dan 2020). After recapitulating the difference between TGH Ibrahim al-Khalidy's perpetual prayer schedule and the Contemporary Calculation System, it was found that TGH Ibrahim al-Khalidy's perpetual prayer schedule was less than 1 minute late by 23%, less than 2 minutes late and greater than 1 minute by 21% and more than 2 minutes late by 24%. While faster is less than 1 minute by 17%, faster is less than 2 minutes greater than 1 minute by 8%, and faster than 2 minutes by 6%. The largest difference for the "later" category at Isha prayer time for East Lombok is 5 minutes 39, while the "faster" category at Maghrib prayer time for Mataram and West Lombok is 3 minutes 46 seconds [40]. An overall comparison for each prayer time between TGH. Ibrahim Al-Khalidys timetable of perpetual prayer times being earlier or later can be seen in the table below:

From the table, it can be seen that the percentage between the eternal prayer schedule of TGH. Ibrahim Al-Khalidy is 69% more and 31% faster. This percentage shows that the perpetual prayer schedule of TGH Ibrahim al-Khalidy is greater than the percentage of delay with the prayer schedule of the contemporary system calculation with the location of Mataram, West Lombok, East Lombok, Central Lombok, and North Lombok. The largest percentage of delay occurs for East Lombok and then Central Lombok. The delay is because of TGH. Ibrahim Al-Khalidy's timetable does not use the Regional Time Conversion for East Lombok and Central Lombok. This delay is an astronomical consequence of taking coordinates from the western part of the island of Lombok. Thus, the eastern part which should be traveled by the sun first follows the western part which is slower to be travelled by the sun.

TGH. Ibrahim Al-Khalidy's "late" position on the timetable has resulted in other areas where it can be said that "prayers are by the entry of the Zuhr, Asar, Maghrib, Isha, and Fajr prayer times". However, it becomes a significant problem when praying before the prayer time or earlier than the actual prayer time. Especially during the holy month of Ramadan in waiting for the time to break the fast or maghrib time. Breaking the fast before its time. Thus, the prayer schedule is better late than early.

The "faster" time difference between TGH. Ibrahim Al-Khalidy's perpetual prayer schedule and the contemporary calculation system are greatest at maghrib and dawn prayer times. This time difference is because the perpetual prayer schedule of TGH Ibrahim Al-Khalidy has not used time correction in the form of Refraction, Altitude of Place, and Semi Diameter. This time correction is very influential on the determination of Maghrib, Fajr, and Isha times. So, to perfect this prayer schedule, it needs to be added with time correction to match the condition of the Sun's position as a marker of the entry of prayer time. The perpetual prayer schedule model compiled by TGH. Ibrahim Al-Khalidy by combining the island of Lombok into one region can be justified astronomically, because the difference in latitude between districts and cities on Lombok Island is not greater than 1 .

The northernmost boundary of the island of Lombok is at the coordinates 08°13'48.43'' LS | 116°13'48.43''BT while the southernmost boundary of the island of Lombok is at the coordinates47 08°51'31'' LS | 116°16'29.07''BT. The difference in latitude between the northernmost and southern boundaries is about a 36-minute arc. So, with this small difference in latitude value, the island of Lombok can be categorized as one region.

The categorization of the island of Lombok as one region makes the prayer timetable more practical for use by the community. This is the advantage of the timetable compiled by TGH Ibrahim Al-Khalidy. However, in terms of accuracy, the data and calculation algorithms need to be adjusted to the latest developments in algorithms and astronomical data. Thus, the prayer timetable is more in line with the condition of the Sun marking the entry of prayer time and is practically used by the people on the island of Lombok [41].

The Perpetual Prayer Schedule compiled by TGH. Ibrahim Al-Khalidy not only serves as a technically accurate guide for worship but also has significant spiritual and social contributions in supporting various Sustainable Development Goals (SDGs). Below is a detailed description of the contributions of TGH. Ibrahim Al-Khalidy's Perpetual Prayer Schedule to the achievement of the SDGs:

SDG 3 – Good Health and Well-being

The accuracy of the prayer schedule compiled by TGH. Ibrahim Al-Khalidy plays an important role in establishing a disciplined and consistent worship routine for Muslims on Lombok Island. This routine not only fulfills religious obligations but also functions as a mechanism for stress management and mental health improvement. Various psychological studies show that regular spiritual practices, such as timely prayer, can reduce levels of anxiety and depression, as well as enhance inner peace and emotional balance. Furthermore, disciplined prayer times encourage a regular lifestyle, including better sleep and rest patterns, which overall support physical health. In the context of the Lombok community, the accurate schedule facilitates congregational worship in mosques or prayer rooms, strengthening social bonds and emotional support among community members, which is also an important factor in social well-being.

SDG 4 – Quality Education

This prayer schedule not only functions as a worship guide but also as a medium for preserving and developing traditional knowledge of astronomy (Falak) and Islamic jurisprudence (fiqh) that has been passed down through generations. By integrating traditional calculation methods with modern astronomy, this schedule exemplifies how science and culture can synergize. This opens opportunities for richer and more contextual religious education, where the younger generation not only learns worship rituals but also understands the scientific and philosophical foundations behind them. Educational and training programs adopting this schedule can improve learning quality, strengthen cultural

SDG 11 – Sustainable Cities and Communities

The accuracy and uniformity of prayer times facilitated by this schedule strengthen social cohesion and cultural identity among the people of Lombok. Organized and uniform worship practices create a strong sense of unity and solidarity, which are fundamental foundations for sustainable and harmonious communities. Moreover, this schedule supports the management of public spaces and worship facilities, such as mosques and prayer rooms, which serve as centers for social and cultural activities. With an accurate schedule, religious activities can be better planned, increasing community participation and strengthening social networks. This contributes to building inclusive, safe, and resilient communities, in line with the principles of SDG 11.

SDG 16 – Peace, Justice, and Strong Institutions

The spiritual values contained in the prayer schedule reinforce ethical and moral norms that underpin peace and social justice. The punctuality of prayer reflects individual discipline and responsibility, contributing to social order and strengthening religious institutions. Additionally, this schedule supports the creation of harmony among citizens by promoting values of tolerance and mutual respect in worship practices. The collaborative process in compiling and updating the schedule, involving various parties, also reflects principles of transparency and participation, which are important elements in building strong and accountable institutions.

SDG 17 – Partnerships for the Goals

The compilation and updating of this Perpetual Prayer Schedule are the results of close partnerships among traditional astronomy experts, modern astronomers, religious leaders, and local communities. This synergy demonstrates how cross-disciplinary and crosssector collaboration can produce innovative and sustainable solutions. These partnerships not only strengthen the technical validity of the schedule but also ensure that cultural and spiritual values are preserved. This collaborative model can serve as an example for the development of other sustainable development programs, where tradition and innovation go hand in hand to achieve common goals.

From these contributions, it is evident that TGH. Ibrahim Al-Khalidy's Perpetual Prayer Schedule plays a multifaceted role that goes beyond its technical function as a timekeeper for worship. The schedule is an important instrument in strengthening mental and social health, improving the quality of religious education, building sustainable communities, reinforcing peace and social justice, and facilitating strategic partnerships for sustainable development. Therefore, maintaining and developing this schedule with a scientific and collaborative approach is crucial to holistically support the achievement of the SDGs on Lombok Island, while also preserving its rich cultural and spiritual heritage.