export declare function isGregorianLeapYear(year: number): boolean;
export declare function dayOfYear(year: number, month: number, day: number): number;
export declare function daysFromCivil(year: number, month: number, day: number): number;
export declare function dayOfWeekFromCivil(year: number, month: number, day: number): number;
export interface IsoWeekDate {
    isoYear: number;
    week: number;
}
export declare function isoWeekYearAndWeek(year: number, month: number, day: number, dayOfWeek: number): IsoWeekDate;