export declare const digits: (s: string) => string;
export declare function maskDateEU(text: string): string;
export declare function maskTimeHM(text: string): string;
export declare function maskSingle(text: string, enableTime: boolean): string;
export declare function maskRange(text: string, _enableTime: boolean): string;
export declare const pad2: (n: number) => string;
export type UtcIsoString = string;
export type DateOnlyString = string;
export declare function isUtcIsoString(v: unknown): v is UtcIsoString;
export declare function isDateOnlyString(v: unknown): v is DateOnlyString;
export declare function utcMillisFromIso(iso: UtcIsoString): number;
/** Convert a local DateTime to a UTC ISO string (Z). */
export declare function isoFromLocalDate(dLocal: Date): UtcIsoString;
/**
 * Build a *local* Date from y/m/d/hh/mm and return UTC ISO string (Z).
 * This keeps the UI meaning "local wall time", while emitting a stable UTC instant.
 *
 * DST NOTE:
 * If the requested local wall time does not exist (spring-forward), JS will auto-correct.
 * We detect that and return null so caller can handle it (e.g., show validation error).
 */
export declare function isoFromLocalParts(y: number, m0: number, // 0-based
d: number, hh?: number, mm?: number): UtcIsoString | null;
/** For anchoring the calendar safely from a UTC ISO string. */
export declare function localDateFromIso(iso: UtcIsoString): Date | null;
/** Date-only: build 'YYYY-MM-DD' from local parts */
export declare function dateOnlyFromLocalParts(y: number, m0: number, d: number): DateOnlyString;
/** Parse 'YYYY-MM-DD' into a local Date at midnight */
export declare function localDateFromDateOnly(s: DateOnlyString): Date | null;
/** Compare date-only strings by UTC date-only time (stable ordering) */
export declare function compareDateOnly(a: DateOnlyString, b: DateOnlyString): number;
export declare function toMaskedFromDate(d: Date, enableTime: boolean): string;
export declare function parseLooseDateOrDateTime(input: string): Date | null;
export declare function parseLooseRange(input: string): {
    start: Date;
    end: Date;
} | null;