import { BasicDate, ICalendar } from '../Core';
export declare class GregorianCalendar implements ICalendar {
    /**
     * Test if a year is leap year or not.
     * @param {number} year
     * @returns {boolean} Boolean
     */
    isLeap(year: number): boolean;
    /**
     * Convert Gregorian Date to Julian day number (JDN)
     * @param {number} day
     * @param {number} month
     * @param {number} year
     * @returns {number} jdn (Julian Date Number)
     */
    toJDN(year: number, month: number, day: number): number;
    /**
     * Convert Julian day number (JDN) to Gregorian Date.
     * @param {number} jdn (Julian Date Number)
     * @returns {object} Date object.
     */
    fromJDN(jdn: number): BasicDate;
    validator(year: number, month: number, day: number): boolean;
    /**
     * Convert Julian day number (JDN) to Year.
     * @param {number} jdn Julian day number
     * @returns {number} year
     */
    private jdnToYear;
}