The start of the Islamic month of Rajab is determined by the lunar calendar and will begin on December 20, 2025, according to projections from Egyptian astronomical research [[1]]. This sighting,calculated to occur after a conjunction at 3:45 a.m. local time in Cairo on December 19th, is notable for its predicted brevity-wiht the crescent moon visible over Mecca for just 14 minutes-and is considered a rare astronomical event not expected to recur for another seven years.The timing of this new moon holds cultural and religious importance, prompting anticipation for the observance of traditions like the “white days” of voluntary fasting.
New Lunar Month Begins in December, Astronomers Say
The new month of Rajab is expected to begin on December 20, 2025, according to Egyptian astronomical research. The sighting of the crescent moon marking the start of the Islamic month will occur directly after the conjunction at 3:45 a.m. local time in Cairo on December 19, 2025.
Astronomers note the new moon will remain visible in the skies over Mecca for 14 minutes. This event is drawing attention as some experts are calling it a rare opportunity, stating it won’t be repeated for seven years.
The timing of the new moon’s birth before dawn has been described as a significant astronomical event. Experts have cautioned that this is a “once in a lifetime” opportunity to witness.
The observance of the “white days” – a period of voluntary fasting – within the month of Rajab is also anticipated in 2026.
Historically, the name Rajab holds significance in Arab culture, predating Islam. Its origins and meaning have been embedded in the region’s traditions for centuries.
