/**
 * Returns the number of days since the given date.
 * If the given date is in the future, it returns 0.
 *
 * @example
 * daysSince("2000-01-01") // > 8000
 *
 * @param date The date to calculate from.
 * @returns The number of days since the given date.
 */
export declare function daysSince(date: Date | string | number | null): number;