Today's Moon Phase
Moon phase
Time until the new moon —
Moon phases and the Hijri month
The moon orbits the Earth in a synodic month of about 29.53 days: it begins at the new moon, when it lies between the Earth and the sun and is invisible, then grows as a waxing crescent to the full moon at mid-month, before waning back to the new moon. The Hijri months follow this same moon, which is why each month has 29 or 30 days.
Religious note: the astronomical new moon does not automatically mark the start of the Hijri month. An Islamic month begins with the naked-eye sighting of the crescent after sunset, or by completing 30 days, and the crescent is rarely visible on the conjunction night itself. Countries differ between sighting and calculation, which is why this site shows the official Umm al-Qura dates with a one-day adjustment switch.
Frequently asked questions
What is the new moon?
The new moon is the astronomical birth of the lunar month: the moon lies between the Earth and the sun and is completely invisible. The crescent then grows night after night.
Does the new moon mean the Hijri month has started?
Not automatically. An Islamic month begins with the sighting of the crescent after sunset or the completion of 30 days, and the crescent cannot be seen on the conjunction night itself, which is why official bodies use computed calendars such as Umm al-Qura.
How long is one lunar cycle?
The moon takes about 29.53 days (the synodic month) to orbit the Earth, which is why Hijri months have 29 or 30 days.
How is the moon phase computed on this site?
By an astronomical calculation based on the mean synodic cycle of 29.53 days, accurate enough for the phase and illumination. Determining the start of months is not this tool’s job; it follows the official calendar.