Chrono Ambiguity Flag

Flags the dates chrono-node parsed CONFIDENTLY and the dates it parsed AMBIGUOUSLY -- so a plausible wrong `Date` does not silently reach a booking, an invoice due date, or a scheduled job.

Built for chrono-node 2.10.1, verified by installing it as a real node_modules dependency and reading the version from disk -- not inferred from a badge, a summary or a changelog. Not affiliated with, endorsed by, or an official product of the chrono-node project; chrono-node is the real work here and full credit belongs to Wanasit Tanakitrungruang and its contributors. This package runs BESIDE chrono-node, depends on it as a normal npm package, and never forks, vendors or redistributes any of its source.

THE SILENT FAILURE. chrono-node returns a `Date`. It does not return a confidence. A string a human would have to ask a clarifying question about parses just as cleanly as an unambiguous one -- a bare numeric date whose day/month order depends on locale, a weekday with no week, a month with no year, a time with no date, a relative phrase with no anchor. Every one produces a real `Date` object that passes every type check downstream.

The failure is not a parse error. It is a booking three months out, an invoice due on the wrong day, or a job that runs a year early -- discovered by a customer, not by a stack trace.

THIS PACKAGE SEPARATES THE TWO. It reports which parses rest on an assumption, names the assumption, and says what the alternative reading would have been -- so a caller can ask the clarifying question a human would have asked, instead of committing to whichever reading the parser's locale default produced.

VERIFIED: 149 tests, measured by running the suite.

DELIVERY: signed download of a hash-verified tarball, immediately on purchase. Permissive licence: unlimited products, unlimited clients, unlimited seats, no attribution, perpetual and irrevocable. One restriction, do not republish the source as source.

Interface

What you call, and what comes back. Types and signatures only — the implementation ships with the source.

  export function daysInUtcMonth(year: number, month1to12: number): number;
  export function shiftByMonthsUtc(reference: Date, monthsDelta: number): MonthShiftResult;
  export function flagAmbiguity( input: string, chronoResult: ChronoParsedResult, context: AmbiguityContext, ): AmbiguityVerdict;
  export function hasRelativeAnchor(text: string): boolean;
  export function parseMonthsDelta(text: string): number | null;
  export function checkEndOfMonthArithmetic( chronoText: string, _chronoResult: ChronoParsedResult, context: AmbiguityContext, ): AmbiguityFlag | null;
  export function checkMissingReferenceInstant( chronoText: string, chronoResult: ChronoParsedResult, context: AmbiguityContext, ): AmbiguityFlag | null;
  export function checkNumericDateOrder( chronoText: string, chronoResult: ChronoParsedResult, context: AmbiguityContext, enGB: typeof en.GB, ): AmbiguityFlag | null;
  export function checkSameWeekdayModifier( chronoText: string, chronoResult: ChronoParsedResult, context: AmbiguityContext, ): AmbiguityFlag | null;
  export function checkTimezoneNaive( chronoText: string, chronoResult: ChronoParsedResult, context: AmbiguityContext, ): AmbiguityFlag | null;
  export function checkTwoDigitYearCentury( chronoText: string, chronoResult: ChronoParsedResult, context: AmbiguityContext, ): AmbiguityFlag | null;
  export function matchWeekdayModifier(text: string): WeekdayModifierMatch | null;

  export type DateOrderConvention = "month-day" | "day-month";