import type { DateRange, DateLib } from "../types/index.js";
/**
 * Add a day to an existing range.
 *
 * The returned range takes in account the `undefined` values and if the added
 * day is already present in the range.
 *
 * @group Utilities
 */
export declare function addToRange(date: Date, range: DateRange | undefined, 
/** @ignore */
dateLib?: DateLib): DateRange;