import type { ChartDateFormat, ChartDateFormatStyle } from '../types.js';
export type DateSourceFormat = 'mm/yyyy' | 'yyyy-mm' | 'yyyy-mm-dd' | 'dd.mm.yyyy';
export type DateGranularity = 'month' | 'day';
export type DetectedDateSource = {
    format: DateSourceFormat;
    granularity: DateGranularity;
};
/**
 * Detect a single shared source date format across all non-empty categories.
 * Returns `null` if any category fails to match the format picked from the
 * first non-empty entry.
 */
export declare function detectDateFormat(categories: string[]): DetectedDateSource | null;
export declare function parseDateCategory(value: string, source: DetectedDateSource): Date | null;
export declare function defaultStyleFor(granularity: DateGranularity): ChartDateFormatStyle;
/**
 * Format a single category string. Returns the original string if it does not
 * match the source format, so partially-bad data still renders something.
 */
export declare function formatDateCategory(value: string, source: DetectedDateSource, format: ChartDateFormat | undefined, locale: string | undefined): string;