The Unified Global Hijri Calendar (UGHC) principle of global synchronization ensures that the beginning of a new month follows a single, unified date worldwide similar to the Gregorian calendar system. There are several requirements and parameters to ensure the calendar maintains consistency and accuracy while aligning with astronomical and global considerations.
Requirements of UGHC
The UGHC must meet the following requirements as an Islamic calendar. First, the Islamic calendar must be a system that accommodates both religious and worldly affairs. Second, the Islamic calendar must be based on the kamariah (lunar) months, where the duration does not exceed 30 days and is not less than 29 days. Third, the Islamic calendar must be a unifying calendar, ensuring that the same date applies worldwide on a single day. Fourth, the Islamic calendar must not allow a group of Muslims in any region of the Earth to start a new month before it is certain that the calendar parameters have been met somewhere on Earth. Fifth, the Islamic calendar must not delay the entry of a new month for a group of Muslims in any region while the crescent (hilal) is already clearly visible on their horizon.
UGHC Parameters
The UGHC (Unified Global Hijri Calendar) must meet the following parameters. First, the entire world is considered a unified matlak; the new lunar month begins simultaneously across all regions. Second, the new month starts if, before 24:00 GMT, any location on Earth meets the criteria: an elongation of 8° or more and a hilal (crescent) altitude of at least 5° above the horizon at sunset. Third, if the above criteria are met after midnight (24:00 GMT), the new month still begins under the following conditions: 1) The criteria are fulfilled somewhere on Earth, and ijtima‘ (conjunction) has occurred in New Zealand before dawn; and 2) The criteria mentioned in point (1) are met within the continental landmass of the Americas.
