Calculation Analysis of Crescent Height Muh. Manshur Al-Batawi in The Book of Sullam Nayyirain

The book of Sulam Nayyirain has an important role in astronomy, its presence being the beginning of the emergence of astronomy science in Indonesia in 1925. The classification of hisab hakīkī bi at-taqrībī for the early month of hisab system in the book does not make it ignored and not studied for students of astronomy , Until now this book still has a "place" for students of astronomy. The al-Manshuriyah group with the calendar of Sulam Nayyirain system is the real proof to the existence of the Nayyirain Embroidery in Indonesia.

KH. Muhammad Manshur al-Battawi is one of the prominent figures in Indonesia of the famous Makkah-Madinah alumni in the thought of astronomy is as it is known that Sulam Nayyirain is one of his fundamental works (Khazin, 2005: 24).

Muhammad Manshur al-Batawi who is a prominent figure as a true teacher by Betawi people both in the religious sciences, especially in astronomy. Noted there are 19 works that have been produced, including: Sulam Nayyirain, Chulashātul Jadwāl, Kaifiyatul Amāl Ijtimā', Khusūf Wal Kusūf, Mizānul I "tidāl, Washilātut Thullāb, Jadwālu Dawāirul Falākiyah, Majmū" u Arba "Rasāil fi Masāilil Hilāl, Jadwāl Farāid, Al-lu "lū Ulmankhum Fi Khulāsoh Mabāhist Sittah Ulmmm, and many other works which essentially deal with the science of astronomy and pharaids (Manshur, 2008: 6).

Guru Manshur (nickname) in his application often uses the Sulam Nayyirain in the early stages of Ramadan, Shawwal and Zulhijah, even to this day the famous al-Manshuriyah calendar whose reckoning uses the reckoning system of Sulam Nayyirain.

Various cases of early determination of the hilal (crescent) in Indonesia, the results of reckoning Sulam Nayyirain often produce higher predictions of hilāl larger than other reckoning systems that are often different, both with the reckoning belonging to the system of hakikī bi at-tahkīkī and contemporary. An example is in the determination of 1 Syawal 1428 H (2007 M). Sulam Nayyirain gives high predictions hilāl = 03 degrees 37 minutes 'and age of hilāl = 14 minutes 28 seconds for Indonesia. This result differs considerably from the calculations of hisab hakīkī bi at-tahkīkī and contemporary.

Guru Manshur in Sulay Nayyirain did not specify the attitude of the hilāl's high criterion which is the minimum limit to be seen visually. He only expounded various scholars' opinions on the high criteria of hilāl, and also mentioned the judge's attitude to be taken when addressing the testimony of a person who claimed to have seen hilāl (Manshur, tt .: 12).

Guru Manshur also mentions in his book that scholars' differing opinions on Hilāl's high criteria without mentioning who the 'ulama' are perusing each of these criteria. He merely deduced that in his opinion Hilāl can be seen as a very relative and conditional boundary. The advice of Guru Manshur in the book of Sulam Nayyirain which he said is about the judge's attitude as a continuation of the criteria of the scholars' mentioned earlier. In this case referring to the government.

Guru Manshur asserted that the judge in determining and drawing the conclusions of the results of rukyah must be on a careful and conscientious attitude. This is due to the difficulty of hilāl to dirukyah and avoid the results of the results of rukyah which indicates errors in merukyah or there lie element of his testimony.
Based on Guru Mansur's thoughts above it can be concluded that in the early determinations of Master Mansur not focusing on rukyatul hilāl, he from the beginning was committed to the concept of ijtimā' qabla al-ghurūb mentioned earlier as the argument on the turn of the hijri month based on hisab in Sulam Nayyirain.
Guru Manshur's statement in his treatise stating that the early adoption system of the hijri month in the book of Sulam Nayyirain was guided by ijtimā'. This is because if ijtimā' occurs when the Sun before it sets then, after the Sun sets is entering the new moon and vice versa, if ijtimā' occurs after the ghurūb is fixed after the Sunset does not enter the new moon (Manshur, tt .: 12).

This opinion is aligned and supported by Hilali's high reckoning system that exists in the book of Sulam Nayyirain. This is due to the Hilāl Sulam Nayyirain's altitude formula = (ghurūb - ijtimā') / 2 or x 30'

The argument of this formula is that on the basis of the Moon leaving the Sun to the east at 12 degrees every day of the night (twenty-four hours) from here it certainly does not seem to be taken into account the daily motion of the Moon and the Sun (Izzuddin 1997: 66).

Hisab crescent height of Sulam Nayyirain based on research resulted that the results of calculations according to the author's statement of the book, that if ijtima' happened qabla al-ghurūb then Hilāl certainly crescent on the horizon. On the contrary, if ijtima' occurs ba'da al-ghurūb hilāl Hilāl can be ascertained by reckoning Sulam Nayyirain, crescent is still under the horizon.

This is because in the recitation of Sulam Nayyirain the time from ijtima' to ghurub divided by 2 or multiplied by 30 minutes with the argument of daily movement of the Moon against Earth of 12 degrees. The simplicity of this reckoning value results in the prediction of Sulam Nayyirain higher than the high-prediction data of modern hilāl astromony, such as Ephemeris.