A DATE TO REMEMBER
What did the Moon look like
on your birthday?
Choose a birthday or a date you want to remember. Explore its Moon phase and illumination, compare two dates, and keep a Moon portrait as an image.
How is a birthday Moon calculated?
The calculation uses noon on your chosen date in the selected city's time zone. The Moon's phase changes as we see different amounts of its sunlit half from Earth. NASA Moon Phases ↗
This tool shows approximate phases from 1900 to 2100. It is not a birth-time ephemeris or an actual photograph from that date. The phase changes during the day; use an authoritative ephemeris when precision matters.
What does comparing two Moons tell you?
You can compare how much of the Moon was lit and whether it was waxing or waning on each date. Similar or complementary shapes do not establish relationship compatibility. Think of the pair as a visual keepsake for two special dates.
How do I save the card?
After calculating, choose “Save Moon card as PNG” for a 1200×1200 image. Dates are hidden on the card by default; include them if you choose. Calculation and image creation happen inside your browser.