Toward Muslim Unity: Understanding the Global Unified
Hijri Calendar (GUHC) in the Observance of Ramadan
Islam is a religion that upholds order and knowledge. Amid
today’s advances in space technology, Muslims are presented with a
revolutionary methodological innovation: The Global Unified Hijri Calendar
(GUHC). This concept is not merely a timekeeping tool, but a scientific
effort to realize unity in worship among Muslims around the world.
What Is KHGT?
Scientifically, GUHC is a calendrical system that
establishes the principle of one day, one date worldwide. Based on the
outcomes of the International Congress on the Global Islamic Calendar held in
Turkey (2016), this system seeks to unify the Islamic calendar so that there
will no longer be differences among countries in starting Ramadan or celebrating
Eid.
Its scientific foundation rests on robust astronomical
criteria:
Global Imkanur Rukyat (Global Crescent Visibility):
If the crescent (hilal) meets the visibility criteria anywhere on Earth before
00:00 GMT, then the entire world is considered to have entered a new lunar
month.
Strict Parameters:
The minimum requirements for the new month are a crescent altitude of at least
5 degrees and an elongation (angular distance between the Moon and the Sun) of
at least 8 degrees.
The Growth of the Crescent:
Scientifically, the crescent continues to grow over time. If in Indonesia the
crescent is not yet visible (because sunset occurs earlier), a few hours later
it will certainly be higher and visible in western regions of the Earth such as
the Americas. GUHC recognizes the crescent’s visibility in the western
hemisphere as valid for residents in the eastern hemisphere (including
Indonesia).
The Challenge of Ramadan 1447 AH (2026 CE)
In 2026, we face a dynamic scientific situation. According
to GUHC calculations, 1 Ramadan 1447 AH falls on Wednesday, 18 February 2026.
Why might this differ from the government/MABIMS prediction
(19 February)?
Astronomically, at sunset on 17 February, the crescent’s
altitude in Indonesia remains low (below the local 3-degree criterion).
However, in the western hemisphere (such as Alaska or the Americas), the
crescent’s altitude is significantly higher and satisfies the international
5-degree criterion. For proponents of GUHC, a verified sighting in another part
of the world is valid for all Muslims globally.
Why Is KHGT Important for Da’wah?
From a da’wah perspective, implementing a single global
calendar carries profound significance:
Certainty in Worship (Hifz ad-Din):
With a global astronomical calculation system, worship schedules can be
predicted with high precision decades in advance. This facilitates
international planning for ‘umrah, hajj, and zakat distribution.
Manifestation of Muslim Unity:
Just as Muslims face a single Ka‘bah in prayer, GUHC invites Muslims to begin
fasting and celebrate Eid on the same day, removing geographical boundaries
that have long caused differences.
Islam as Pro-Science:
These differences are not theological divisions, but developments in
methodological ijtihad. They demonstrate that Islam remains open to modern
space research for the benefit of humanity.
Conclusion
Differences in determining the beginning of a lunar month
constitute a scientific domain that should be approached with maturity and
mutual respect (tasamuh). However, moving toward a single global
calendar represents a grand vision to demonstrate the strength and unity of the
Muslim world in the modern era.
May we observe Ramadan with devotion, guided by knowledge
and conviction.
#GlobalHijriCalendar
#GUHC
#Ramadan1447AH
#AstronomicalCalculation
#MuslimUnity



