Methodology
How people are selected
Every person in the dataset comes from a structured source with a stable identifier, primarily Wikidata, and must have a birth date known to the day. We prioritise wealthy and entrepreneurial people, then scientists, athletes, artists and historical figures with enough documentation to be interesting. Nothing is generated by an AI model; models only help draft descriptions and propose candidates that people then verify.
What “billionaire” means
A person is listed as a billionaire only when a publisher on our wealth allowlist (Forbes, Bloomberg, the Sunday Times Rich List, Hurun, or a regulatory filing) reported an estimate of at least $1 billion, and we show the date of that estimate. Wealth changes. We never present a figure as live or current.
How wealth is sourced
Each estimate stores a value or a range, a currency, an “as of” date and its source. When two sources disagree by more than a quarter we show a range instead of pretending precision.
How characteristics are documented
A characteristic is attached to a person only when a verbatim quote from a biography, interview or profile supports it, the quote was mechanically found in that source, and a human approved it. We then report counts: “persistence appears in 8 of 12 documented profiles.” These are descriptions of people in the dataset, not predictions about anyone sharing the date.
How duplicates and dates are handled
Records merge only on matching identifiers, or on identical name and birth date plus a matching company or occupation. Ambiguous matches are held for review. February 29 is a full date with its own page; people born on it are counted as celebrating on March 1 in non-leap years for age calculations.
Images and text
Images come from Wikimedia Commons under public-domain or Creative Commons licences and carry their attribution. Short descriptions adapted from Wikipedia are attributed under CC BY-SA.
Limitations
Coverage is uneven across dates, wealth estimates lag reality, and documented characteristics exist only for a subset of people. Dates without enough verified people show an honest empty state and are not submitted to search engines. Dataset last generated 2026-09-03.