import { DateRange } from '../core/date-range';
/**
 * DateId: yyyymmdd
 *    (Month: 01 ~ 12.)
 * tbd: support other formats like "yyyy/mm/dd" or "yyyy-mm-dd"  as well?
 * ("yyyymmdd" format is good because it can be directly cast to number, e.g., for comparison, etc.)
 */
export declare namespace DateIdUtil {
    function isDateIdValid(dateId: string): boolean;
    function convertToDate(dateId: string): Date;
    function convertToId(date: Date): string;
    /**
     * Returns today's 'dateId' (yyyymmdd).
     */
    function getTodayId(): string;
    function getTomorrowId(): string;
    function getYesterdayId(): string;
    function getNextDayId(dateId: string): string;
    function getNthDayId(dateId: string, dayN?: number): string;
    function convertToDateRange(dateId: string): DateRange;
    function getISODateString(dateId: (string | null), excludeTimePart?: boolean): string;
    function fromISODateString(str: string): string;
    function getLocaleDateString(dateId: (string | null)): string;
    function getDateString(dateId: (string | null), sep?: (string | null)): string;
    function convertToEpochMillis(dateId: string): number;
    function convertFromEpochMillis(millis: number): string;
    /**
     * Returns Sunday id of the given week.
     *
     * @param dateId Reference dateId. Today is used by default.
     */
    function getSundayOfWeek(dateId?: string): string;
    /**
     * Returns the id of the first day of the given month.
     *
     * @param dateId Reference dateId. Today is used by default.
     */
    function getFirstDayOfMonth(dateId?: string): string;
    /**
     * Returns the number of days until the same day next month.
     *
     * @param dateId Reference dateId. Today is used by default.
     */
    function getNumberOfDaysForMonth(dateId?: string): number;
    /**
     * Returns the number of days from the same day in the previous month.
     *
     * @param dateId Reference dateId. Today is used by default.
     */
    function getNumberOfDaysForPreviousMonth(dateId?: string): number;
    /**
     * Returns the number of days between the same day next month and the same day the following month.
     *
     * @param dateId Reference dateId. Today is used by default.
     */
    function getNumberOfDaysForNextMonth(dateId?: string): number;
}