{
  "name": "How often February 29 comes around, by span of dates",
  "desc": "February 29 days and total days in four date spans (one four-year span, 1901–2096, 1901–2099 and one 400-year cycle), with the share as a fraction and as one day in N.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "The Yardstick Almanac",
  "url": "https://theyardstickalmanac.com/scale/leap-day-birthdays/",
  "from": [
    "Gregorian leap-year rule, Explanatory Supplement to the Astronomical Almanac, ch. 15, sec. 15.4.2"
  ],
  "how": "Compiled by The Yardstick Almanac from the data listed",
  "data_by": [
    "Computed from the Gregorian leap-year rule (Explanatory Supplement to the Astronomical Almanac, ch. 15, sec. 15.4.2), 2026-11-01, CC BY 4.0"
  ]
}