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

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

import { isValidDateTimeUnit } from "../plain/validate/index.js";
/**
 * Normalize a date-time unit string to its singular form.
 *
 * - Accepts singular ("day"), plural ("days"), and already-singular forms.
 * - Returns the original string if it is not a recognized DateTimeUnit.
 * - Singular counterpart of `resolveDurationUnit`, which normalizes to plurals.
 *
 * @param unit raw unit string from caller input
 * @returns normalized singular unit string, or the original if not recognized
 */
export function resolveDateTimeUnit(unit) {
    if (isValidDateTimeUnit(unit)) {
        return unit;
    }
    if (unit.endsWith("s")) {
        const singular = unit.slice(0, -1);
        if (isValidDateTimeUnit(singular)) {
            return singular;
        }
    }
    return unit;
}