The moon on the night you were born
Of all the facts on a birth poster, the moon phase is the one people check twice. There's something quietly personal about knowing the sky: whether you arrived under a full moon or a thin waxing crescent that barely lit the way to the hospital.
How it's calculated
Moon phases repeat every 29.53 days (the synodic month), so any date's phase can be computed from a known new moon. From your birth date the cycle position maps to one of eight phases: New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Waning Crescent. Our poster maker computes it automatically and prints it with the phase symbol.
The folklore (for fun, not physics)
New Moon — beginnings; folklore paints these people as initiators.
Waxing phases — growth and building; the "work in progress" temperament.
Full Moon — intensity and visibility; the dramatic entrance crowd (and yes, every maternity nurse has an opinion about full-moon nights).
Waning phases — reflection and letting go; the old souls.
None of this is science — studies find no birth-rate spike on full moons — but as birthday-card material it beats "have a great day".
A detail that elevates a gift
"You were born under a Waning Gibbous" is the line on the poster people photograph and send to their mom to verify. That conversation is the gift working.
Get this letter personalized in 2 minutes
Our generator fills in your details, the correct legal citations and current mailing addresses — and builds the rest of the pack around it. Free preview, no signup.
Frequently asked questions
How accurate is a computed moon phase?
Phase calculations from the synodic cycle are accurate to within hours — more than enough to name the phase on a given night.
Does the moon phase depend on where you were born?
The phase is essentially the same worldwide on a given date; only the moon's visibility and rise time differ by location.
Do more babies really arrive on full moons?
It's a beloved maternity-ward legend, but large studies find no significant effect. Great poster line, bad statistics.