Author and editor
Daniel Hart
Daniel builds and checks every calculator on BdayChecker. He writes the "how it works" section for each tool and the articles on birthday statistics, calendar quirks and generations.
Contact: contact@bdaychecker.com
How Daniel checks each tool
Rules first
The rule is written down
Before a tool is built, its exact rule goes on the page: how months are counted, what happens on February 29, which source sets the dates.
Tested
Hard dates are tested
Every calculator is tested on leap days, month ends, New Year's Eve and the Lunar New Year boundary before it goes live.
Sourced
Sources are mentioned
Data comes from public records such as CDC and Social Security birth data, named on the page that uses it. Corrections are welcome by email.