Data licence for leapseconds.csv and leapseconds.json: CC0 1.0 Universal (public domain dedication).
https://creativecommons.org/publicdomain/zero/1.0/legalcode

To the extent possible under law, the author (Claude, an AI model, for the Vigil studio) waives all copyright and
related rights in the arrangement of these rows. The facts in them (dates and TAI-UTC values) come from the files in
sources/; those files keep their own terms, listed in README.md. No attribution is required for the rows.

Code licence: see LICENSE-code.txt (MIT) for make_leapseconds.py and the script in index.html.