Islamic Crescents' Observation Project

Papers about Crescents, Prayer Times,
Qiblah, Hijric Calendar, ...etc.



Arabic Papers


  • Author: Ahmad Ridwan.
  • Name in English: Comparison of Hijrah And Gregorian Calendars
  • Name in Arabic: مقارنة بين التقويم الميلادي و الهجري
  • Year of Publication: 2003.
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  • Author: Hamid Alnaimiy.
  • Name in English: Hejric Month Crescents Between Visibility and Astronomical Calculations.
  • Name in Arabic: أهلة الشهور الهجرية بين الرؤية الشرعية والحسابات الفلكية
  • Year of Publication: 2005.
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  • Author: Hasan Basurah.
  • Name in English: Sighting the Crescent by Observatories, and the Opinion if It Was Seen by Naked Eye but Not by Observatories.
  • Name in Arabic: ترائي الهلال بواسطة المراصد والقول إذا لم ير بها ورئي بالعين
  • Year of Publication: 2008.
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  • Author: Hasan Bilani.
  • Name in English: Evaluate The Percentage of Error in Determining Dates of Holly Feast in Syria.
  • Name in Arabic: دراسة فلكية إحصائية لتحديد نسب الخطأ في بدايات الأشهر الهجرية في سورية
  • Year of Publication: 2001.
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  • Author: Hasan Bilani.
  • Name in English: A Geodetic Study For Determining of Qibla Direction.
  • Name in Arabic: دراسة جيوديزية لتحديد اتجاه القبلة
  • Year of Publication: 2003.
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  • Author: Hasan Hamad, Mansoor Ashkefah and Mohammad Al-Hashani.
  • Name in English: Determination The Begining of The Lunar Months.
  • Name in Arabic: ايجاد بدايات الشهور القمرية
  • Year of Publication: 2003.
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  • Author: Sharaf Al-Qodah.
  • Name in English: Lunar Month Determination Between Hadith and Modern Science.
  • Name in Arabic: ثبوت الشهر القمري بين الحديث النبوي والعلم الحديث
  • Year of Publication: 1999.
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  • Author: Jalal Edeen Khanji.
  • Name in English: Detairmening Qibla Direction in Fiqeh, Astronomy And Engineering.
  • Name in Arabic: القبلة وتحديدها بين الفقه والفلك والهندسة
  • Year of Publication: 2003.
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  • Author: Jalal Edeen Khanji.
  • Name in English: Asr Prayer Time: A Critique of the Current Approach and A Suggestion of an Alternative Method.
  • Name in Arabic: أول وقت صلاة العصر - نقد معيار طريقة الحساب الفلكية المعاصرة و عرض معيار بديـل صحيح
  • Year of Publication: 2006.
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  • Author: Mohammad Al-Marakishi.
  • Name in English: The Truth Opinion Clarification for Solar Depression Angle for Fajer and Isha
  • Name in Arabic: إيضاح القول الحق في مقدار انحطاط الشمس وقت طلوع الفجر وغروب الشفق
  • Year of Publication: 1975.
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  • Author: Mohammad Khan.
  • Name in English: Crescent Sighting Using Uml Al Qura Calendar in Saudi Arabia to Determine Ramadan And Eid Ul Fitir of 1422 AH And Its Implications for Unity in Different Countries.
  • Name in Arabic: رؤية الهلال باستخدام تقويم أم القرى لتحديد رمضان و عيد الفطر لعام 1422 هـ و تأثيره على الوحدة بين بلاد المسلمين
  • Year of Publication: 2001.
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  • Author: Mohammad Odeh.
  • Name in English: Evaluation of The Error Percentage in Determining The Beginning of Lunar Months in Jordan (During The Past Half-Century).
  • Name in Arabic: تقويم نسب الخطأ في تحديد أوائل الأشهر الهجرية في الأردن خلال النصف قرن الماضي
  • Year of Publication: 1999.
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  • Author: Mohammad Odeh.
  • Name in English: Hejric-Gregorian Date Conversion.
  • Name in Arabic: التحويل ما بين التقويمين الهجري و الميلادي
  • Year of Publication: 2001.
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  • Author: Mohammad Odeh.
  • Name in English: Calculating Islamic Prayer Times.
  • Name in Arabic: حساب مواقيت الصلاة
  • Year of Publication: 2001.
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  • Author: Mohammad Odeh.
  • Name in English: Universal Hejric Calendar (UHC).
  • Name in Arabic: التقويم الهجري العالمي
  • Year of Publication: 2001.
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  • Author: Mohammad Odeh.
  • Name in English: Lunar Crescent Sighting Versus Astronomical Calculations.
  • Name in Arabic: الهلال بين الحسابات الفلكية والرؤية
  • Year of Publication: 2004.
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  • Author: Mohammad Odeh.
  • Name in English: The Difference Between The Crescent And The New Moon.
  • Name in Arabic: الفرق بين الهلال و تولد الهلال
  • Year of Publication: 2004.
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  • Author: Mohammad Odeh.
  • Name in English: Geocentric Moon Phases Viruses Topocentric Moon Phases (Conjunction Times for Mecca ).
  • Name in Arabic:الفرق بين أطوار القمر المركزية و السطحية (مواعيد الاقتران بالنسبة لمدينة مكة المكرمة )ا
  • Year of Publication: 2004.
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  • Author: Mohammad Odeh.
  • Name in English: IT Applications to Construct Universal Hejric Calendar
  • Name in Arabic:تطبيقات تكنولوجيا المعلومات لإعداد تقويم هجري عالمي
  • Year of Publication: 2007.
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  • Author: Mohammad Odeh.
  • Name in English: Estimating Fajer and Isha Times When They Disappear in The Area Between Latitude 48.6 and 66.6
  • Name in Arabic:تقدير موعدي صلاة الفجر والعشاء عند اختفاء العلامات الفلكية في المنطقة ما بين خطي عرض 48.6° و66.6°
  • Year of Publication: 2009.
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  • Author: Saleh Belfakih.
  • Name in English: The Beginning of Asr Prayer Time, from Approximate to Definite.
  • Name in Arabic: دخول وقت صلاة العصر من التقريب إلى التحقيق
  • Year of Publication: 2007.
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  • Author: Salman Shaikh.
  • Name in English: Which Hilaal to Follow ? Reasons for Islamic Dates Confusion And Their Solution.
  • Name in Arabic: أي هلال نتبع ؟ أسباب الاختلاف في التواريخ و الحلول
  • Year of Publication: 2001.
  • Download Part One. | Download Part Two.


  • Author: Zaki Al-Mostafa.
  • Name in English: Limits of Time Difference.
  • Name in Arabic: حدود فوارق التوقيت
  • Year of Publication: 2003.
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  • Author: Zaki Al-Mostafa and Yaser Hafiz.
  • Name in English: Umm Al-Qurah Calendar (Saudi Official Calendar).
  • Name in Arabic: تقويم أم القرى (التقويم السعودي الرسمي)ا
  • Year of Publication: 2001.
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English Papers


  • Author: Abdul Haq Sultan.
  • Name in English: Sun Apparent Motion and Salat Times.
  • Name in Arabic: حركة الشمس الظاهرية و مواقيت الصلاة
  • Year of Publication: 2004.
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  • Author: Abdul Haq Sultan.
  • Name in English: Explaining and Calculating The Length of The New Crescent Moon.
  • Name in Arabic: شرح و حساب طول الهلال القمري
  • Year of Publication: 2005.
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  • Author: Abdul Haq Sultan.
  • Name in English: "Best Time" for The First Visibility of The Lunar Crescent
  • Name in Arabic: أفضل وقت لأول رؤية للهلال القمري
  • Year of Publication: 2006.
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  • Author: Abdul Haq Sultan.
  • Name in English: First Visibility of The Lunar Crescent: Beyond Danjon’s Limit
  • Name in Arabic: بداية رؤية الهلال قبل حد دانجون
  • Year of Publication: 2007.
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  • Author: Abdurrazak Ebrahim.
  • Name in English: Crescent Observation And The Visibility of The Hilaal.
  • Name in Arabic: رصد الهلال و رؤيته
  • Year of Publication: 2003.
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  • Author: Baharrudin Zainal.
  • Name in English: A Selective Literature Review of Young Moon Crescent Visibility Studies.
  • Name in Arabic: مطالعة انتقائية لدراسات رؤية الهلال
  • Year of Publication: 2001.
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  • Author: Bernard Yallop and C.Y. Hohenkerk.
  • Name in English: A note on sunrise, sunset and twilight times and on the illumination conditions during twilight.
  • Name in Arabic: ملاحظة على مواعيد شروق وغروب الشمس والشفق وأوضاع الإضاءة أثناء الشفق
  • Year of Publication: 1996.
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  • Author: Bernard Yallop.
  • Name in English: A Method for Predicting the First Sighting of The New Crescent Moon.
  • Name in Arabic: طريقة للتنبؤ برؤية الهلال الجديد
  • Year of Publication: 1997.
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  • Author: Bradley Schaefer.
  • Name in English: Visibility of The Lunar Crescent.
  • Name in Arabic: رؤية هلال القمر
  • Year of Publication: 1988.
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  • Author: Bradley Schaefer.
  • Name in English: Length of The Lunar Crescent.
  • Name in Arabic: طول هلال القمر
  • Year of Publication: 1991.
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  • Author: Bradley Schaefer.
  • Name in English: The Length of The Lunar Month.
  • Name in Arabic: طول الشهر القمري
  • Year of Publication: 1992.
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  • Author: Bradley Schaefer, Imad Ahmad and LeRoy Doggett.
  • Name in English: Records for Young Moon Sightings.
  • Name in Arabic: سجلات رؤية الهلال الجديد
  • Year of Publication: 1993.
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  • Author: Bradley Schaefer and LeRoy Doggett.
  • Name in English: Visibility of The Lunar Crescent.
  • Name in Arabic: رؤية هلال القمر
  • Year of Publication: 1994.
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  • Author: Bradley Schaefer.
  • Name in English: Lunar Crescent Visibility.
  • Name in Arabic: رؤية هلال القمر
  • Year of Publication: 1996.
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  • Author: David McNaughton.
  • Name in English: A Universal Islamic Calendar.
  • Name in Arabic: تقويم إسلامي عالمي
  • Year of Publication: 1997.
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  • Author: Francois Querci.
  • Name in English: An Aircraft Equipment for New Lunar Crescent Observations.
  • Name in Arabic: استخدام الطائرة لرصد الهلال
  • Year of Publication: 2001.
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  • Author: John Caldwell and David Laney.
  • Name in English: First Visibility of The Lunar Crescent.
  • Name in Arabic: الرؤية الأولى لهلال القمر
  • Year of Publication: 2001.
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  • Author: Louay Fatoohi, F. Richard Stephenson and Sheta Al-Dargazelli.
  • Name in English: The Danjon Limit of First Visibility of The Lunar Crescent
  • Name in Arabic: حد داجون لرؤية الهلال
  • Year of Publication: 1998.
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  • Author: Mohammad Ilyas.
  • Name in English: Lunar Crescent Visibility Criterion and Islamic Calendar.
  • Name in Arabic: معيار رؤية الهلال القمري و التقويم الإسلامي
  • Year of Publication: 1994.
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  • Author: Mohammad Khan.
  • Name in English: Crescent Sighting Using Uml Al Qura Calendar in Saudi Arabia to Determine Ramadan And Eid Ul Fitir of 1422 AH And Its Implications for Unity in Different Countries.
  • Name in Arabic: رؤية الهلال باستخدام تقويم أم القرى لتحديد رمضان و عيد الفطر لعام 1422 هـ و تأثيره على الوحدة بين بلاد المسلمين
  • Year of Publication: 2001.
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  • Author: Mohammad Odeh.
  • Name in English: New Criterion For Lunar Crescent Visibility.
  • Name in Arabic: معيار جديد لرؤية هلال القمر
  • Year of Publication: 2006.
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  • Author: Muhammad Hafiz and Aamer Akmal.
  • Name in English: Justification for Using The Universal Hejric Calendar (UHC) for The Determination of Correct Islamic Dates And Reduction of Takalluf (Burden) from A Shariah perspective.
  • Name in Arabic: مبرر اعتماد التقويم الهجري العالمي لتحديد بدايات التواريخ الإسلامية و تقليل التكلف من وجهة نظر شرعية
  • Year of Publication: 2001.
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  • Author: Muhammad Shahid Qureshi
  • Name in English:Computational Astronomy and the Earliest Visibility of Lunar Crescent.
  • Name in Arabic: الفلك الحاسوبي والرؤية المبكرة للهلال القمري
  • Year of Publication: 2005.
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  • Author: Nidhal Guessoum and Karim Meziane
  • Name in English: Visibility of the Thin Lunar Crescent: The Sociology of an Astronomical Problem (A Case Study).
  • Name in Arabic: رؤية الهلال القمري النحيل
  • Year of Publication: 2000.
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  • Author: S. Kamal Abdali.
  • Name in English: On The Crescent’s Visibility.
  • Name in Arabic: حول رؤية الهلال
  • Year of Publication: 1979.
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  • Author: S. Kamal Abdali.
  • Name in English: On The Crescent’s Visibility.
  • Name in Arabic: حول رؤية الهلال
  • Year of Publication: 1979.
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  • Author: Saleh Al-Shidhani.
  • Name in English: Laser Assisted Crescent Observations.
  • Name in Arabic: رصد الهلال بمساعدة الليزر
  • Year of Publication: 2003.
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  • Author: Salman Shaikh.
  • Name in English: Which Hilaal to Follow ? Reasons for Islamic Dates Confusion And Their Solution.
  • Name in Arabic: أي هلال نتبع ؟ أسباب الاختلاف في التواريخ و الحلول
  • Year of Publication: 2001.
  • Download Part One. | Download Part Two.


  • Author: Thomas Djamaluddin.
  • Name in English: Calendar Conversion Program Used To Analyze Early History of Islam.
  • Name in Arabic: استخدام برنامج لتحويل التقويم لتحليل الأحداث القديمة في الإسلام
  • Year of Publication: 2001.
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  • Author: Thomas Djamaluddin.
  • Name in English: Re-evaluation of Hilaal Visibility in Indonesia
  • Name in Arabic: إعادة تقييم رؤية الهلال في اندونيسيا
  • Year of Publication: 2001.
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