rules/dates.json

{
  "rules_version": "1.1.0",
  "description": "Date recognition and ISO normalisation.",
  "patterns": [
    "(?:令和|平成|昭和|大正|明治)\\s*(?:\\d{1,2}|元)\\s*年(?:\\s*\\d{1,2}\\s*月(?:\\s*\\d{1,2}\\s*日)?)?",
    "\\d{4}\\s*年\\s*\\d{1,2}\\s*月\\s*\\d{1,2}\\s*日",
    "\\d{4}\\s*年\\s*\\d{1,2}\\s*月",
    "(?<![0-9A-Za-z])\\d{4}[-/.]\\d{1,2}[-/.]\\d{1,2}(?![0-9A-Za-z])",
    "(?<![0-9A-Za-z])\\d{4}[-/]\\d{1,2}(?![-/.\\d])",
    "(?<![0-9A-Za-z])(?:Jan|January|Feb|February|Mar|March|Apr|April|May|Jun|June|Jul|July|Aug|August|Sep|Sept|September|Oct|October|Nov|November|Dec|December)\\.?\\s+\\d{1,2}(?:st|nd|rd|th)?,?\\s+\\d{4}(?![0-9A-Za-z])",
    "(?<![0-9A-Za-z])\\d{1,2}(?:st|nd|rd|th)?\\s+(?:Jan|January|Feb|February|Mar|March|Apr|April|May|Jun|June|Jul|July|Aug|August|Sep|Sept|September|Oct|October|Nov|November|Dec|December)\\.?,?\\s+\\d{4}(?![0-9A-Za-z])",
    "(?<![0-9A-Za-z])(?:Jan|January|Feb|February|Mar|March|Apr|April|May|Jun|June|Jul|July|Aug|August|Sep|Sept|September|Oct|October|Nov|November|Dec|December)\\.?,?\\s+\\d{4}(?![0-9A-Za-z])",
    "(?<![0-9A-Za-z])(?:FY)\\s?\\d{4}(?![0-9A-Za-z])",
    "\\d{4}\\s*年度",
    "(?<![0-9])\\d{4}\\s*年(?![0-9度])"
  ],
  "relative_date_pattern": "(?:昨年|一昨年|来年|再来年|今年|本年|先月|今月|来月|先週|今週|来週|昨日|本日|今日|明日|明後日|現在|最近|近年|直近|先般|過去\\d+年|今後\\d+年|\\byesterday\\b|\\btoday\\b|\\btomorrow\\b|\\blast\\s+(?:year|month|week|quarter)\\b|\\bnext\\s+(?:year|month|week|quarter)\\b|\\bthis\\s+(?:year|month|week|quarter)\\b|\\brecently\\b|\\bcurrently\\b|\\bnowadays\\b)",
  "era_offsets": {
    "令和": 2018,
    "reiwa": 2018,
    "平成": 1988,
    "heisei": 1988,
    "昭和": 1925,
    "showa": 1925,
    "大正": 1911,
    "taisho": 1911,
    "明治": 1867,
    "meiji": 1867
  },
  "month_names": {
    "jan": 1,
    "january": 1,
    "feb": 2,
    "february": 2,
    "mar": 3,
    "march": 3,
    "apr": 4,
    "april": 4,
    "may": 5,
    "jun": 6,
    "june": 6,
    "jul": 7,
    "july": 7,
    "aug": 8,
    "august": 8,
    "sep": 9,
    "sept": 9,
    "september": 9,
    "oct": 10,
    "october": 10,
    "nov": 11,
    "november": 11,
    "dec": 12,
    "december": 12
  },
  "notes": [
    "Output granularity is preserved: YYYY, YYYY-MM or YYYY-MM-DD.",
    "Era year N maps to offset + N, so 令和1 == 2019.",
    "Relative expressions are counted but never become claims.",
    "Word boundaries are NOT \\\\b: in 契約は2024-01-05に both sides are word characters, so \\\\b never fires and the date was invisible.",
    "FY2024 and 2024年度 both normalise to 2024. Fiscal-year start months differ by country: a known false positive."
  ]
}