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What did the moon look like on your birthday?
Enter your birthday and see the moon phase on that day, how much of it was lit and how it looked. It is free and there is nothing to sign up for.
How to find the moon phase on the day you were born
The phase of the Moon depends on the angle between the Sun, the Earth and the Moon. That angle can be worked out for any date, past or future, with astronomical formulas.
This calculator does it for ten in the evening on the date you enter, in your time zone. It then shades a real photograph of the Moon, taken by NASA, to show how it looked.
We compared the results with astronomical ephemerides for dates from 1930 to 2035: the difference in the illuminated percentage is under one point.
The eight phases of the Moon
New moon
The Moon cannot be seen: its lit side faces the Sun.
Waxing crescent
A thin sliver of light in the evening sky, growing every day.
First quarter
A half moon, with the lit half growing towards full.
Waxing gibbous
More than half lit, a few days before the full moon.
Full moon
The whole disc lit, visible all night long.
Waning gibbous
Just past full, still large and bright.
Last quarter
A half moon again, now losing light each night.
Waning crescent
A thin sliver before dawn, about to start over.
This is how they look from the northern hemisphere. From the south, the Moon appears rotated.
Frequently asked questions
What did the moon look like on the day I was born?
Enter your date of birth in the calculator above. You will see the phase, the illuminated percentage and an image of how the Moon looked that night.
Is this a real photo of the Moon from that day?
No. It is a real photograph of the Moon, from NASA, shaded to match the phase calculated for your date. There is no photo of the Moon for every single night.
Do I need to know what time I was born?
No. The phase changes little over one day: a few points of illumination. The calculator uses ten in the evening on that date.
Does the moon phase depend on where I was born?
The phase is practically the same all over the world on a given date. What changes is the orientation: from the southern hemisphere it looks rotated. That is what the southern hemisphere box is for.
What does it mean to be born under a certain phase?
Astronomy gives it no meaning. Many traditions do, each in its own way. Here we show the real phase; the meaning is yours to give.
Can I compare my birth moon with my partner’s or my baby’s?
Yes. Press “Add another date” to see both moons side by side. You can also turn them into a print with both names.
Take your moon home
Turn the moon of your date into a print to frame, with your name and your colors. Or give the whole sky of that night with a star map.
Design my moon print See the star map