Birthday facts
Born on March 31.
Everyone born on March 31 is a Aries — ruled by Mars, first, loudest, already gone. The stone is aquamarine, the flower daffodil, and the day is shared with René Descartes and Johann Sebastian Bach.
Your book
Born on March 31? Add the year.
Then it is a pop-up book: the sky the day you arrived, the No. 1 that week, the president, what a stamp cost, your life in weeks, and who was exactly your age when they did the thing they are known for — and at the end, a birthday poster of the day, engraved, to take home. One field. The date lives after the # in the link, which no server sees — nothing about you leaves your browser.
Making it for someone else? Send it as a pop-up birthday card.
The old books say
Aries, March 21 to April 19.
The first sign, and the tradition treats it that way: the Ram is the one who goes first — through the door, into the argument, off the cliff. Ruled by Mars, a fire sign, and the books credit it with courage, impatience and a short memory for grudges, which is a generous way of saying it has already moved on. Its people are supposed to start things. Finishing them is what the other eleven are for.
Astrology, reported rather than endorsed — the astronomy is the part of the book that is real.
Good company
Also born on March 31.
The names most looked up among everyone who shares the day — leaning on the ones who last.
On this day
What March 31 has seen.
It is International Transgender Day of Visibility.
The calendar
When March 31 falls.
A Tuesday in 2026, a Wednesday in 2027, a Friday in 2028, a Saturday in 2029, and a Sunday in 2030.