Waning Crescent at birth
Waning Crescent illustration
A thinning crescent returns just before the next new moon, often visible in the east before sunrise.
The last crescent tips the cycle back toward darkness and the next new moon.
Place in the cycle
The Moon takes a bit over twenty-nine and a half days to return to the same phase. The Waning Crescent is the eighth of the eight labels this site uses between one new moon and the next.
How this site estimates your phase
The birthday calculator has your date, not your birth minute. We evaluate a simple average lunar cycle at local noon and map that progress into eight named windows. That is good enough for curiosity and teaching; orbital ephemerides used by observatories are tighter when you need precision.
Read more in methodology or return to the moon phases hub.
Common questions
What does a Waning Crescent look like?
From Earth you see illumination that is small and shrinking. Exact appearance still depends on your latitude, the Moon's path, and weather.
How does the calculator decide I had a Waning Crescent?
It estimates phase at local noon on your birth date with a mean synodic-month model, then bins the result into one of eight classic names.
Can the label be wrong without a birth time?
Yes, near phase boundaries. Without clock time and location, neighboring names can be equally plausible.