Who founded the tz database, also called the Olson database?

Arthur David Olson founded the tz database, also called the Olson database.

The project began as a practical effort to collect time-zone information for computer systems. Its data describes local clock rules and transitions, allowing programs to convert times accurately across regions and dates. The nickname “Olson database” honors Olson as its founding contributor.

The project’s origins go back to 1986 or earlier. Over time, it became a collaborative public resource rather than the work of one person. Paul Eggert has been the principal maintainer of the database since 2005, while Olson has continued making many changes to the reference code.

A frequent mix-up is confusing the founder with the modern organizational steward. The database moved under ICANN’s responsibility in 2011, and IANA distributes it, but those later roles do not change Olson’s place in the project’s history. The same data is now commonly called tzdata or the IANA time-zone database.