@burglekitt/gmt/dist/internal/calendarSystemIds.js

Temporal-based date and time utilities with timezone support and polyfill integration

// Maps GMT's public CalendarSystem identifiers to the Temporal/Intl calendar identifiers
// they wrap. "gregorian" maps to "iso8601" (Temporal's default, era-free calendar) rather
// than "gregory" (which carries BCE/CE eras) since GMT's existing unannotated ISO strings
// are already iso8601-calendared — this keeps "gregorian" round-trips a no-op.
//
// "islamic-tabular" maps to Temporal's "islamic-tbla" id (its name for the same
// arithmetic/astronomical-epoch tabular calendar). "islamic-umalqura" resolves through
// Temporal's built-in Umm al-Qura implementation rather than a table GMT ports itself —
// per E1's "no ported leap-year tables or arithmetic" precedent, the polyfill already
// carries the correct tabulated/algorithmic data, so a GMT-owned copy would only add a
// second, divergence-prone source of truth.
//
// "taiwan" maps to Temporal's "roc" id (Republic of China calendar — the same calendar
// react-aria's TaiwanCalendar wraps under a different name). "japanese", "buddhist", and
// "persian"/"indian" match Temporal's own ids directly.
//
// "ethiopic-amete-alem" maps to Temporal's "ethioaa" id (Ethiopic calendar anchored to the
// Amete Alem/"Year of the World" epoch, ~5493 BCE — a single continuous era, never resets).
// "ethiopic" and "coptic" match Temporal's own ids directly; both share the Ethiopic
// family's 13-month structure (12 x 30 days + a 5/6-day Pagume/Nasie) but differ in epoch —
// "ethiopic" additionally resets to the Amete Mihret/"Incarnation" era at its own epoch
// (~AD 8), which is why it needs the same eraYear-based string handling as "japanese" (see
// calendarDateString.ts's isEraBased).
export const temporalCalendarIds = {
    gregorian: "iso8601",
    hebrew: "hebrew",
    "islamic-civil": "islamic-civil",
    "islamic-tabular": "islamic-tbla",
    "islamic-umalqura": "islamic-umalqura",
    japanese: "japanese",
    buddhist: "buddhist",
    taiwan: "roc",
    persian: "persian",
    indian: "indian",
    ethiopic: "ethiopic",
    "ethiopic-amete-alem": "ethioaa",
    coptic: "coptic",
};
export function isCalendarSystem(value) {
    return value in temporalCalendarIds;
}
// Reverse of temporalCalendarIds — needed because some GMT calendar identifiers (e.g.
// "islamic-tabular") don't match Temporal's own id for the same calendar ("islamic-tbla"),
// so a PlainDate's `calendarId` can't be used directly as GMT's string annotation.
const gmtCalendarSystemIds = Object.fromEntries(Object.entries(temporalCalendarIds).map(([gmtId, temporalId]) => [
    temporalId,
    gmtId,
]));
export function calendarSystemIdFromTemporal(temporalId) {
    const gmtId = gmtCalendarSystemIds[temporalId];
    if (!gmtId) {
        throw new Error(`Unsupported Temporal calendar id: ${temporalId}`);
    }
    return gmtId;
}