export declare enum CalendarType {
    English = 0,
    Gregorian = 1,
    Julian = 2
}
/**
 * Western date ot Julian day number. Credit4 Gregorian 2 JD: (w2j)
 * @see https://cool-emerald.blogspot.com/2013/06/algorithm-program-and-calculation-of.html#jdn
 * @param date western date object
 * @param startOfGregorian start of Gregorian calendar in Julian day number (default 2361222)
 * @param calendarType calendar type (default English)
 * @returns Julian day number
 */
export declare const westernToJulianDayNumber: (date: Date, startOfGregorian?: number, calendarType?: CalendarType) => number;