Birthday facts
Born on December 31.
Everyone born on December 31 is a Capricorn — ruled by Saturn, will outwork you, quietly. The stone is turquoise, the flower narcissus, and the day is shared with Val Kilmer and Henri Matisse.
Your book
Born on December 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
Capricorn, December 22 to January 19.
The Sea-Goat, ruled by Saturn, the taskmaster, and the books make it the sign of the long game — the climb, the plan, the thing built to last. An earth sign, credited with discipline, dry humour and an old head on young shoulders that grows into itself around forty. Its people are said to arrive late to their own success and stay. The tradition respects Capricorn the way one respects a well-kept ledger.
Astrology, reported rather than endorsed — the astronomy is the part of the book that is real.
Good company
Also born on December 31.
The names most looked up among everyone who shares the day — leaning on the ones who last.
On this day
What December 31 has seen.
It is Saint Sylvester's Day (Western Christianity).
The calendar
When December 31 falls.
A Thursday in 2026, a Friday in 2027, a Sunday in 2028, a Monday in 2029, and a Tuesday in 2030.