The concept of a Unified Global Hijri Calendar represents a significant aspiration for many Muslims, aiming to establish a standardized lunar calendar system that is universally recognized. To realize this vision, six essential criteria must be met.
First, the unified global hijri calendar must encompass both religious and civil aspects. This means that the calendar should not only dictate the timing of Islamic religious observances, such as the beginning of Ramadan and Eid, but also serve as a practical tool for everyday life and administrative purposes. Quran 2:189 emphasizes the moon as a means for people to determine time and hajj (pilgrimage).
Second, the unified global hijri calendar must be based on the lunar cycle. The Islamic calendar has always been tied to the phases of the moon. Quran 9:36 affirms that the Islamic year consists of twelve lunar months. Additionally, the calendar must align with the synodic month, which typically lasts between 29 and 30 days.
Third, the unified global hijri calendar must be truly global. A single date should be observed worldwide. This might necessitate a re-evaluation of the criteria for sighting the new moon and astronomical calculations, as lunar visibility varies across different regions. Given the spherical nature of the Earth, the visibility of the crescent moon is not uniform. Therefore, the unified global hijri calendar must take this into account while adhering to the principles outlined in the Quran and Hadith. Quran 21:92 emphasizes the unity of the Muslims, and a global calendar would be a tangible manifestation of this unity.
Fourth, another criterion is the occurrence of the astronomical conjunction, or ijtima, when the moon position is between the Earth and the sun. During this phase, the moon is invisible from Earth. The new lunar month cannot begin before this event. Quran 36:39 indicates that the moon follows a predetermined course, and the unified global hijri calendar must align with these celestial phenomena.
Fifth, the unified global hijri calendar must consider the possibility of sighting the crescent moon. Both astronomical calculations (hisab) and lunar observation (rukyat) should be taken into account. A common standard for the moon’s visibility, such as a minimum altitude of 5 degrees and an elongation angle of 8 degrees, could bridge the gap between the two methods.
Finally, the beginning of a new lunar month cannot be delayed if the crescent moon has been sighted or if the criteria for its visibility have been met. A hadith of the Prophet Muhammad states, “When you see the crescent then fast, and when you see it, stop fasting.” This principle emphasizes the importance of commencing the new month as soon as the crescent moon is visible. In other words, regions where the moon is sighted or where the conditions for its sighting are met should be considered the reference point for other regions.
These six interconnected criteria form the foundation of the unified global hijri calendar. While the concept may be unfamiliar and different from the calendars used in many countries, particularly in Indonesia, the unified global hijri calendar holds the potential to unify the global Muslims. Despite the challenges, the aspiration of having a single calendar that unites all Muslims remains a worthy goal.
