HOME · GLOSSARY
Standard definitions for Hijri dates, moon sighting, sacred seasons, and the calendar terms used across IslamCal.
About Islamic dates: Hijri dates may differ by location and methodology. IslamCal labels dates as Confirmed, Calculated, Estimated, or Locally observed. Learn how dates are determined →
IslamCal uses readable English spellings consistently—such as Rabi Al-Awwal, Jumada Al-Awwal, Dhul Qa‘dah, and Dhul Hijjah—while giving Arabic and a closer scholarly transliteration where it helps identification.
أ هـ · After Hijrah
Abbreviation for years after the Hijrah. IslamCal writes dates such as 1448 AH.
عرفة · ‘Arafah
The 9th of Dhul Hijjah; the central day of Hajj and a highly recommended fasting day for non-pilgrims. Related events.
أيام البيض · Ayyām al-Bīḍ
The White Days: the 13th, 14th, and 15th of each Hijri month, when voluntary fasting is recommended.
Before Hijrah
A modern historical label for years before the Hijrah; it is less standardized than AH.
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A date derived from a stated calendar calculation. It is useful for planning but is not presented as an observed sighting.
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A date officially established by the relevant authority according to its adopted method.
الاقتران · Ijtimā‘
The astronomical alignment associated with the new moon. It is not the same as the first visible crescent.
إمكان رؤية الهلال
Whether the young crescent may be seen after sunset, based on factors including altitude, elongation, moon age, atmosphere, and location. Learn more.
ذو الحجة · Dhul Hijjah
The twelfth Hijri month, containing Hajj, Arafah, Eid al-Adha, and the Days of Tashriq. Month guides.
عيد الأضحى · ‘Īd al-Aḍḥā
The Festival of Sacrifice on 10 Dhul Hijjah, continuing into the days of sacrifice.
عيد الفطر · ‘Īd al-Fiṭr
The festival on 1 Shawwal marking the completion of Ramadan.
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A provisional date that may change when an authority announces or a local community observes the month.
هلال · Hilāl
The first visible crescent used to identify the beginning of a lunar month.
الهجرة · Hijrah
The Prophet Muhammad’s ﷺ migration from Makkah to Madinah; the event chosen as the starting point of the Hijri era. History.
هجري · Hijrī
Relating to the Islamic lunar calendar whose era is counted from the Hijrah.
حساب · Ḥisāb
Astronomical calculation. It may support planning, visibility assessment, or—under some adopted methods—calendar determination.
اختلاف المطالع · Ikhtilāf al-Maṭāli‘
Difference of lunar horizons: the view that sightings may apply differently across distant regions.
ليلة القدر · Laylat al-Qadr
The Night of Decree in Ramadan, better than a thousand months; sought especially in the last ten nights.
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A date based on a local sighting or a community’s local determination.
مطلع · Maṭla‘
A lunar horizon or region of visibility; used in discussions about whether a sighting applies locally or more widely.
رمضان · Ramaḍān
The ninth Hijri month, during which Muslims fast from dawn to sunset. Explore Ramadan.
رؤية · Ru’yah
Sighting or observation, commonly referring to observing the lunar crescent.
الأشهر الحرم · al-Ashhur al-Hurum
Muharram, Rajab, Dhul Qa‘dah, and Dhul Hijjah—the four months given sacred status in the Qur’an.
أيام التشريق · Ayyām al-Tashrīq
The 11th–13th of Dhul Hijjah, days of remembrance following Eid al-Adha, with special Hajj rulings.
الأيام البيض · al-Ayyām al-Bīḍ
See Ayyam al-Bid: the 13th–15th of each Hijri month.
Arabic transliteration varies. A familiar site spelling is used for navigation; a more precise form may appear beside the Arabic.
