import type { Result } from './result.js';
/**
 * Branded ISO-8601 UTC datetime string ("2026-04-01T00:00:00Z"). Constructed
 * only via `parseIsoDateTime` (or the unsafe escape hatch); every Graph URL
 * built from a calendar-window parameter accepts this type so an unvalidated
 * `string` can't slip through.
 *
 * Audit Hervé-session §C: the previous calendar commands accepted any
 * `z.string().min(1)`, so the LLM had to compute "last week" → ISO by hand.
 * `parseIsoDateTime` turns "7d" / "monday" / "today" / "2026-04-01" / a strict
 * ISO timestamp into the canonical ISO form, so the URL builders stay
 * unchanged.
 */
export type IsoDateTime = string & {
    readonly __brand: 'IsoDateTime';
};
export declare const isoDateTimeUnsafe: (raw: string) => IsoDateTime;
export type DateParseError = {
    readonly type: 'invalid_format';
    readonly input: string;
    readonly hint: string;
};
/**
 * Parse a free-form date input into the canonical `2026-04-01T00:00:00Z`
 * shape (`IsoDateTime`). Returns `err(invalid_format)` with a multi-line
 * hint listing every accepted shape — surfaces directly through the CLI's
 * validation envelope so an LLM gets all the alternatives without an extra
 * round-trip. See `HINT` above for the full list.
 */
export declare const parseIsoDateTime: (rawInput: string, now?: Date) => Result<IsoDateTime, DateParseError>;