Making a family print
Add each child with their name and birthday, then pick a colourway: Midnight, Bone or Dusk. Give it a title, such as "The nights you arrived", and a closing line if you like.
Up to three moons sit in one row; four make a square; five and six make two rows of three. Print at A4 or 8 × 10 in and frame it, or send the phone size to the grandparents.
Questions
How do you work out the phase?
From the positions of the Sun and the Moon at the time you pick, using a shortened version of the formulas in Jean Meeus's Astronomical Algorithms. It's good to a few minutes for full and new moons. If you leave the time blank we use 9 in the evening, your time, the night of that date.
Is the moon picture real?
The moon is a photographic texture and the shadow is drawn from the maths for your date, so a waxing crescent is lit on the right and a waning one on the left, as seen from the northern hemisphere. Choose Southern hemisphere to turn it the way it looked from there.
Can I print it?
Yes. Downloads are PNG files at 300 dpi for A4, 8 × 10 in, 11 × 14 in and a 30 cm square, plus a phone size for sharing. Print at home on matte paper or take the file to any print shop. Free for personal use.
How many dates can I add?
Up to six. With one, the moon fills the print; with more, each gets its own name and date underneath.
Do you keep my dates?
No. Names and dates stay on this device. We count page views without cookies.