{
  "name": "Leap-second ledger, 1972–2027",
  "desc": "The 1972 starting offset, each of the 27 leap seconds with the day that held the extra second, its weekday, TAI−UTC afterward and, from 1995, the Bulletin C that announced it and the days of notice; then the announcement of no leap second at the end of 2026 and the date continuous UTC takes effect. One event per row.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "The Yardstick Almanac",
  "url": "https://theyardstickalmanac.com/calendars/leap-second/",
  "from": [
    "IANA Time Zone Database, leap-seconds.list, updated through IERS Bulletin C 72, expires 2027-06-28 (public domain)",
    "IERS Earth Orientation Center: Leap_Second.dat and Bulletin C issues 10, 13, 16, 30, 36, 43, 49, 52 and 72 (factual values, read 2026-11-01)",
    "BIPM, CGPM 2026 Resolution 5 (DOI 10.59161/CGPM2026RES5E; CC BY 4.0)"
  ],
  "how": "Compiled by The Yardstick Almanac from the data listed",
  "data_by": [
    "IERS Leap_Second.dat and Bulletin C (factual values), IANA leap-seconds.list (public domain) and CGPM 2026 Resolution 5 (BIPM, CC BY 4.0; adapted: date and limit restated), read 2026-11-01; computed 2026-11-01, CC BY 4.0"
  ]
}