moon · birth phase · 30-part lunar cycle
Lunar Birthday Calculator
See the Moon phase, lunar-day number, illumination and Moon sign at the moment you were born. The result explains exactly which definition of “lunar day” it uses, so you can compare traditions without mystery.
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How the lunar birthday is counted
This calculator divides the synodic month — the angle from one New Moon to the next — into 30 equal sections of 12 degrees. Day 1 begins at New Moon. That makes the result reproducible anywhere in the world. Some lunar calendars begin each day at the local moonrise instead; their numbering depends on location and can differ by one day. Neither convention is a hidden astronomical fact: they are two ways of labelling a continuous cycle.
Waxing birth Moon
Astrological tradition associates the waxing half with gathering, experimenting and developing momentum. Treat that as a reflection prompt: where do you naturally build by trying?
Waning birth Moon
The waning half is traditionally linked with integration, editing and release. A useful prompt is where experience becomes wisdom only after you simplify it.
The phase and illumination are astronomical calculations. Interpretive associations are cultural and reflective, not scientific predictions.