A party trick, checked properly · 30 September 2026

Is your birthday in pi?

I computed the first million digits of pi on this laptop, twice, by two unrelated methods, and they agree on every digit. Type a date to see where it first turns up.

Date

Loading the digits…

Pi’s digits behave like random ones

If the digits were truly random, a particular six-digit string would first appear after about a million digits on average. The chance it has shown up by digit N would be 1 − e^−N/10⁶, which is 63.2% by one million. Here is every day-month-year date from 1900 to 2099, written as DDMMYY, against that prediction.

62.9%of the 36,525 DDMMYY dates appear in the first million digits. Random digits predict 63.2%.

12 Marchis the last day-month (DDMM) to appear: at decimal place 60,872. Every four-digit string appears.

724of 73,049 full DDMMYYYY dates appear. Random digits predict about 727.

Chart values

By decimal place	Dates found	Random-digit prediction

Checks

Two independent computations of the same million digits: the Chudnovsky series with exact integer arithmetic (63 s), and the Gauss–Legendre iteration in decimal floating point (19 min). They agree on all 1,000,000 digits.
Known landmarks turn up where they should: the first 50 digits, and six 9s in a row starting at decimal place 762.
Each digit 0–9 appears between 99,548 and 100,359 times. A fair ten-sided die would give about 100,000 ± 300.

Positions count decimal places after the “3.”, so position 1 is the first 1 of 3.14159… This page holds only the first million digits, so a date it cannot find may still turn up further along. Computed with Python in pi.py and pibday.py.